diff --git a/lang/en.yml b/lang/en.yml
index 0fd9893a967..8c6d7171382 100644
--- a/lang/en.yml
+++ b/lang/en.yml
@@ -141,6 +141,10 @@ en:
     IsNullLabel: 'Is Null'
   SilverStripe\Forms\NumericField:
     VALIDATION: "'{value}' is not a number, only numbers can be accepted for this field"
+  SilverStripe\Forms\SearchableDropdownTrait:
+    SELECT: 'Select...'
+    TYPE_TO_SEARCH: 'Type to search...'
+    SELECT_OR_TYPE_TO_SEARCH: 'Select or type to search...'
   SilverStripe\Forms\TextField:
     VALIDATEMAXLENGTH: 'The value for {name} must not exceed {maxLength} characters in length'
   SilverStripe\Forms\TimeField:
diff --git a/src/Forms/SearchableDropdownField.php b/src/Forms/SearchableDropdownField.php
new file mode 100644
index 00000000000..eb740ed7dac
--- /dev/null
+++ b/src/Forms/SearchableDropdownField.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace SilverStripe\Forms;
+
+use SilverStripe\Forms\DropdownField;
+
+class SearchableDropdownField extends DropdownField
+{
+    use SearchableDropdownTrait;
+    
+    // This needs to be defined on the class, not the trait, otherwise there is a PHP error
+    protected $schemaComponent = 'SearchableDropdownField';
+
+    /**
+     * @param string $name
+     * @param string $title
+     * @param DataList|ArrayList|ArrayAccess|array $source
+     * @param mixed $value
+     * @param string $labelField
+     */
+    public function __construct($name, $title = '', $source = [], $value = null, $labelField = 'Title')
+    {
+        // Note that an ancestor constructor will call $this->setSource() which will call
+        // setSource() in this class which throw an exception if $source is not a DataList
+        parent::__construct($name, $title, $source, $value);
+        $this->setLabelField($labelField);
+        $this->addExtraClass('ss-searchable-dropdown-field');
+    }
+}
diff --git a/src/Forms/SearchableDropdownTrait.php b/src/Forms/SearchableDropdownTrait.php
new file mode 100644
index 00000000000..624f16b92b6
--- /dev/null
+++ b/src/Forms/SearchableDropdownTrait.php
@@ -0,0 +1,569 @@
+<?php
+
+namespace SilverStripe\Forms;
+
+use Error;
+use InvalidArgumentException;
+use LogicException;
+use SilverStripe\Control\Controller;
+use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Control\HTTPResponse;
+use SilverStripe\ORM\ArrayList;
+use SilverStripe\ORM\DataList;
+use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\DataObjectInterface;
+use SilverStripe\ORM\Relation;
+use SilverStripe\ORM\SS_List;
+use SilverStripe\ORM\FieldType\DBHTMLText;
+use SilverStripe\View\ArrayData;
+use SilverStripe\ORM\Search\SearchContext;
+use SilverStripe\Security\SecurityToken;
+use SilverStripe\ORM\RelationList;
+use SilverStripe\ORM\UnsavedRelationList;
+
+trait SearchableDropdownTrait
+{
+    private static array $allowed_actions = [
+        'search',
+    ];
+
+    private bool $isClearable = false;
+
+    private bool $isLazyLoaded = false;
+
+    private bool $isMultiple = false;
+
+    private bool $isSearchable = true;
+
+    private int $lazyLoadLimit = 10;
+
+    private string $placeholder = '';
+
+    private ?SearchContext $searchContext = null;
+
+    private bool $useDynamicPlaceholder = true;
+
+    private bool $useSearchContext = false;
+
+    private DataList $sourceList;
+
+    private string $labelField = 'Title';
+
+    /**
+     * Returns a JSON string of options for lazy loading.
+     */
+    public function search(HTTPRequest $request): HTTPResponse
+    {
+        $response = HTTPResponse::create();
+        $response->addHeader('Content-Type', 'application/json');
+        if (!SecurityToken::singleton()->checkRequest($request)) {
+            $response->setStatusCode(400);
+            $response->setBody(json_encode(['message' => 'Invalid CSRF token']));
+            return $response;
+        }
+        $term = $request->getVar('term') ?? '';
+        $options = $this->getOptionsForSearchRequest($term);
+        $response->setBody(json_encode($options));
+        return $response;
+    }
+
+    /**
+     * Get whether the currently selected value(s) can be cleared
+     */
+    public function getIsClearable(): bool
+    {
+        return $this->isClearable;
+    }
+
+    /**
+     * Set whether the currently selected value(s) can be cleared
+     */
+    public function setIsClearable(bool $isClearable): static
+    {
+        $this->isClearable = $isClearable;
+        return $this;
+    }
+
+    /**
+     * Get whether values are lazy loading via AJAX
+     */
+    public function getIsLazyLoaded(): bool
+    {
+        return $this->isLazyLoaded;
+    }
+
+    /**
+     * Set whether values are lazy loaded via AJAX
+     */
+    public function setIsLazyLoaded(bool $isLazyLoaded): static
+    {
+        $this->isLazyLoaded = $isLazyLoaded;
+        if ($isLazyLoaded) {
+            $this->setIsSearchable(true);
+        }
+        return $this;
+    }
+
+    /**
+     * Get the limit of items to lazy load
+     */
+    public function getLazyLoadLimit(): int
+    {
+        return $this->lazyLoadLimit;
+    }
+
+    /**
+     * Set the limit of items to lazy load
+     */
+    public function setLazyLoadLimit(int $lazyLoadLimit): static
+    {
+        $this->lazyLoadLimit = $lazyLoadLimit;
+        return $this;
+    }
+
+    /**
+     * Get the placeholder text
+     */
+    public function getPlaceholder(): string
+    {
+        $placeholder = $this->placeholder;
+        if ($placeholder) {
+            return $placeholder;
+        }
+        // SearchableDropdownField will have the getEmptyString() method from SingleSelectField
+        if (method_exists($this, 'getEmptyString')) {
+            $emptyString = $this->getEmptyString();
+            if ($emptyString) {
+                return $emptyString;
+            }
+        }
+        if ($this->getUseDynamicPlaceholder()) {
+            if ($this->getIsSearchable()) {
+                if (!$this->getIsLazyLoaded()) {
+                    return _t(__TRAIT__ . '.SELECT_OR_TYPE_TO_SEARCH', 'Select or type to search...');
+                }
+                return _t(__TRAIT__ . '.TYPE_TO_SEARCH', 'Type to search...');
+            } else {
+                return _t(__TRAIT__ . '.SELECT', 'Select...');
+            }
+        }
+        return '';
+    }
+
+    /**
+     * Set the placeholder text
+     *
+     * Calling this will also call setHasEmptyDefault(true), if the method exists on the class,
+     * which is required for the placeholder functionality to work on SearchableDropdownField
+     *
+     * In the case of SearchableDropField this method should be used instead of setEmptyString() which
+     * will be remvoved in a future version
+     */
+    public function setPlaceholder(string $placeholder): static
+    {
+        $this->placeholder = $placeholder;
+        // SearchableDropdownField will have the setHasEmptyDefault() method from SingleSelectField
+        if (method_exists($this, 'setHasEmptyDefault')) {
+            $this->setHasEmptyDefault(true);
+        }
+        return $this;
+    }
+
+    /**
+     * Get the search context to use
+     * If a search context has been set via setSearchContext() that will be used
+     * Will fallback to using the dataobjects default search context if a sourceList has been set
+     * Otherwise will return null
+     */
+    public function getSearchContext(): ?SearchContext
+    {
+        if ($this->searchContext) {
+            return $this->searchContext;
+        }
+        if ($this->sourceList) {
+            $dataClass = $this->sourceList->dataClass();
+            /** @var DataObject $obj */
+            $obj = $dataClass::create();
+            return $obj->getDefaultSearchContext();
+        }
+        return null;
+    }
+
+    /**
+     * Set the search context to use instead of the dataobjects default search context
+     *
+     * Calling this will also call setUseSearchContext(true)
+     */
+    public function setSearchContext(?SearchContext $searchContext): static
+    {
+        $this->searchContext = $searchContext;
+        $this->setUseSearchContext(true);
+        return $this;
+    }
+
+    /**
+     * Get whether to use a dynamic placeholder if a normal placeholder is not set
+     */
+    public function getUseDynamicPlaceholder(): bool
+    {
+        return $this->useDynamicPlaceholder;
+    }
+
+    /**
+     * Set whether to use a dynamic placeholder if a normal placeholder is not set
+     */
+    public function setUseDynamicPlaceholder(bool $useDynamicPlaceholder): static
+    {
+        $this->useDynamicPlaceholder = $useDynamicPlaceholder;
+        return $this;
+    }
+
+    /**
+     * Get whether to use a search context instead searching on labelField
+     */
+    public function getUseSearchContext(): bool
+    {
+        return $this->useSearchContext;
+    }
+
+    /**
+     * Set whether to use a search context instead searching on labelField
+     */
+    public function setUseSearchContext(bool $useSearchContext): static
+    {
+        $this->useSearchContext = $useSearchContext;
+        return $this;
+    }
+
+    /**
+     * Get whether the field allows searching by typing characters into field
+     */
+    public function getIsSearchable(): bool
+    {
+        return $this->isSearchable;
+    }
+
+    /**
+     * Set whether the field allows searching by typing characters into field
+     */
+    public function setIsSearchable(bool $isSearchable): static
+    {
+        $this->isSearchable = $isSearchable;
+        return $this;
+    }
+
+    /**
+     * This returns an array rather than a DataList purely to retain compatibility with ancestor getSource()
+     */
+    public function getSource(): array
+    {
+        return $this->getListMap($this->sourceList);
+    }
+
+    /*
+     * @param mixed $source
+     */
+    public function setSource($source): static
+    {
+        if (!is_a($source, DataList::class)) {
+            throw new InvalidArgumentException('Source must be a DataList');
+        }
+        // Setting to $this->sourceList instead of $this->source because SelectField.source
+        // docblock type is array|ArrayAccess i.e. does not allow DataList
+        $this->sourceList = $source;
+        return $this;
+    }
+
+    /**
+     * Get the field to use for the label of the option
+     *
+     * The default value of 'Title' will map to DataObject::getTitle() if a Title DB field does not exist
+     */
+    public function getLabelField(): string
+    {
+        return $this->labelField;
+    }
+
+    /**
+     * Set the field to use for the label of the option
+     */
+    public function setLabelField(string $labelField): static
+    {
+        $this->labelField = $labelField;
+        return $this;
+    }
+
+    public function getAttributes(): array
+    {
+        $name = $this->getName();
+        if ($this->isMultiple && strpos($name, '[') === false) {
+            $name .= '[]';
+        }
+        return array_merge(
+            parent::getAttributes(),
+            [
+                'name' => $name,
+                'data-schema' => json_encode($this->getSchemaData()),
+            ]
+        );
+    }
+
+    /**
+     * Get a list of selected ID's
+     */
+    public function getValueArray(): array
+    {
+        $value = $this->Value();
+        if (empty($value)) {
+            return [];
+        }
+        if (is_array($value)) {
+            $arr = $value;
+            // Normalise FormBuilder values to be like Page EditForm values
+            //
+            // Page EditForm $values for non-multi field will be
+            // [
+            //   0 => '10',
+            // ];
+            // FormBuilder $values for non-multi field will be
+            // [
+            //   'label' => 'MyTitle15', 'value' => '10'
+            // ]
+            if (array_key_exists('value', $arr)) {
+                $val = (int) $arr['value'];
+                return $val ? [$val] : [];
+            }
+            // Page EditForm $values for multi will be
+            // [
+            //   0 => '10',
+            //   1 => '15'
+            // ];
+            // FormBuilder $values for multi will be
+            // [
+            //   0 => ['label' => '10', 'value' => 'MyTitle10', 'selected' => false],
+            //   1 => ['label' => '15', 'value' => 'MyTitle15', 'selected' => false]
+            // ];
+            $firstKey = array_key_first($arr);
+            if (is_array($arr[$firstKey]) && array_key_exists('value', $arr[$firstKey])) {
+                $newArr = [];
+                foreach ($arr as $innerArr) {
+                    $val = (int) $innerArr['value'];
+                    if ($val) {
+                        $newArr[] = $val;
+                    }
+                }
+                return $newArr;
+            }
+        }
+        try {
+            // This is a catch all for unexpected $values that cannot be cast to string e.g. stdClass
+            // We need to cast to string for the ctype_digit() operation below
+            (string) $value;
+        } catch (Error $e) {
+            $value = 0;
+        }
+        if (ctype_digit((string) $value) && $value != 0) {
+            return [(int) $value];
+        }
+        if ($value instanceof SS_List) {
+            return array_filter($value->column('ID'));
+        }
+        if ($value instanceof DataObject && $value->exists()) {
+            return [$value->ID];
+        }
+        // Don't know what value is, handle gracefully. We should not raise an exception here because
+        // of there is a bad data for whatever a content editor will not be able to resolve and it will
+        // render part of the CMS unusable
+        return [];
+    }
+
+    public function Field($properties = []): DBHTMLText
+    {
+        // The entwine class needs to be added so that this field is rendered in an entwine context
+        $this->addExtraClass('entwine');
+        return parent::Field($properties);
+    }
+
+    public function saveInto(DataObjectInterface $record): void
+    {
+        $name = $this->getName();
+        $ids = $this->getValueArray();
+        if (substr($name, -2) === 'ID') {
+            // has_one field
+            $record->$name = $ids[0] ?? 0;
+            $record->write();
+        } else {
+            // has_many / many_many field
+            if (!method_exists($record, 'hasMethod')) {
+                throw new LogicException('record does not have method hasMethod()');
+            }
+            /** @var DataObject $record */
+            if (!$record->hasMethod($name)) {
+                throw new LogicException("Relation $name does not exist");
+            }
+            /** @var Relation $relation */
+            $relationList = $record->$name();
+            // Use RelationList rather than Relation here since some Relation classes don't allow setting value
+            // but RelationList does
+            if (!is_a($relationList, RelationList::class) && !is_a($relationList, UnsavedRelationList::class)) {
+                throw new LogicException("'$name()' method on {$record->ClassName} doesn't return a relation list");
+            }
+            $relationList->setByIDList($ids);
+        }
+    }
+
+    /**
+     * @param Validator $validator
+     */
+    public function validate($validator): bool
+    {
+        return $this->extendValidationResult(true, $validator);
+    }
+
+    public function getSchemaDataType(): string
+    {
+        if ($this->isMultiple) {
+            return FormField::SCHEMA_DATA_TYPE_MULTISELECT;
+        }
+        return FormField::SCHEMA_DATA_TYPE_SINGLESELECT;
+    }
+
+    /**
+     * Provide data to the JSON schema for the frontend component
+     */
+    public function getSchemaDataDefaults(): array
+    {
+        $data = parent::getSchemaDataDefaults();
+        $data = $this->updateDataForSchema($data);
+        $name = $this->getName();
+        if ($this->isMultiple && strpos($name, '[') === false) {
+            $name .= '[]';
+        }
+        $data['name'] = $name;
+        $data['disabled'] = $this->isDisabled() || $this->isReadonly();
+        if ($this->getIsLazyLoaded()) {
+            $data['optionUrl'] = Controller::join_links($this->Link(), 'search');
+        } else {
+            $data['options'] = array_values($this->getOptionsForSchema()->toNestedArray());
+        }
+        return $data;
+    }
+
+    public function getSchemaStateDefaults(): array
+    {
+        $data = parent::getSchemaStateDefaults();
+        $data = $this->updateDataForSchema($data);
+        return $data;
+    }
+
+    /**
+     * Set whether the field allows multiple values
+     * This is only intended to be called from init() by implemented classes, and not called directly
+     * To instantiate a dropdown where only a single value is allowed, use SearchableDropdownField.
+     * To instantiate a dropdown where multiple values are allowed, use SearchableMultiDropdownField
+     */
+    protected function setIsMultiple(bool $isMultiple): static
+    {
+        $this->isMultiple = $isMultiple;
+        return $this;
+    }
+
+    private function getOptionsForSearchRequest(string $term): array
+    {
+        if (!$this->sourceList) {
+            return [];
+        }
+        $dataClass = $this->sourceList->dataClass();
+        $labelField = $this->getLabelField();
+        /** @var DataObject $obj */
+        $obj = $dataClass::create();
+        $key = $this->getUseSearchContext() ? $obj->getGeneralSearchFieldName() : $this->getLabelField();
+        $searchParams = [$key => $term];
+        $hasLabelField = (bool) $obj->getSchema()->fieldSpec($dataClass, $labelField);
+        $sort = $hasLabelField ? $labelField : null;
+        $limit = $this->getLazyLoadLimit();
+        $newList = $this->getSearchContext()->getQuery($searchParams, $sort, $limit);
+        $options = [];
+        foreach ($newList as $item) {
+            $options[] = [
+                'value' => $item->ID,
+                'label' => $item->$labelField,
+            ];
+        }
+        return $options;
+    }
+
+    private function getOptionsForSchema(bool $onlySelected = false): ArrayList
+    {
+        $options = ArrayList::create();
+        if (!$this->sourceList) {
+            return $options;
+        }
+        $values = $this->getValueArray();
+        if (empty($values)) {
+            $selectedValuesList = ArrayList::create();
+        } else {
+            $selectedValuesList = $this->sourceList->filterAny(['ID' => $values]);
+        }
+        // SearchableDropdownField will have the getHasEmptyDefault() method from SingleSelectField
+        // Note that SingleSelectField::getSourceEmpty() will not be called for the react-select component
+        if (!$onlySelected && method_exists($this, 'getHasEmptyDefault') && $this->getHasEmptyDefault()) {
+            // Add an empty option to the start of the list of options
+            $options->push(ArrayData::create([
+                'value' => 0,
+                'label' => $this->getPlaceholder(),
+                'selected' => $selectedValuesList->count() === 0
+            ]));
+        }
+        if ($onlySelected) {
+            $options = $this->updateOptionsForSchema($options, $selectedValuesList, $selectedValuesList);
+        } else {
+            $options = $this->updateOptionsForSchema($options, $this->sourceList, $selectedValuesList);
+        }
+        return $options;
+    }
+
+    private function updateDataForSchema(array $data): array
+    {
+        $selectedOptions = $this->getOptionsForSchema(true);
+        $value = $selectedOptions->count() ? $selectedOptions->toNestedArray() : null;
+        if (is_null($value)
+            && method_exists($this, 'getHasEmptyDefault')
+            && !$this->getHasEmptyDefault()
+        ) {
+            $allOptions = $this->getOptionsForSchema();
+            $value = $allOptions->first()?->toMap();
+        }
+        $data['lazyLoad'] = $this->getIsLazyLoaded();
+        $data['clearable'] = $this->getIsClearable();
+        $data['multi'] = $this->isMultiple;
+        $data['placeholder'] = $this->getPlaceholder();
+        $data['searchable'] = $this->getIsSearchable();
+        $data['value'] = $value;
+        return $data;
+    }
+
+    /**
+     * @var ArrayList $options The options list being updated that will become <options>
+     * @var DataList|ArrayList $items The items to be turned into options
+     * @var DataList|ArrayList $values The values that have been selected i.e. the value of the Field
+     */
+    private function updateOptionsForSchema(
+        ArrayList $options,
+        DataList|ArrayList $items,
+        DataList|ArrayList $selectedValuesList
+    ): ArrayList {
+        $labelField = $this->getLabelField();
+        $selectedIDs = $selectedValuesList->column('ID');
+        /** @var DataObject $item */
+        foreach ($items as $item) {
+            $selected = in_array($item->ID, $selectedIDs);
+            $options->push(ArrayData::create([
+                'value' => $item->ID,
+                'label' => $item->$labelField,
+                'selected' => $selected,
+            ]));
+        }
+        return $options;
+    }
+}
diff --git a/src/Forms/SearchableMultiDropdownField.php b/src/Forms/SearchableMultiDropdownField.php
new file mode 100644
index 00000000000..24e7a7e86f5
--- /dev/null
+++ b/src/Forms/SearchableMultiDropdownField.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace SilverStripe\Forms;
+
+use SilverStripe\Forms\MultiSelectField;
+use SilverStripe\Forms\SearchableDropdownTrait;
+
+class SearchableMultiDropdownField extends MultiSelectField
+{
+    use SearchableDropdownTrait;
+
+    // This needs to be defined on the class, not the trait, or else a there is a PHP error
+    protected $schemaComponent = 'SearchableDropdownField';
+
+    /**
+     * @param string $name
+     * @param string $title
+     * @param DataList|ArrayList|ArrayAccess|array $source
+     * @param mixed $value
+     * @param string $labelField
+     */
+    public function __construct($name, $title = '', $source = [], $value = null, $labelField = 'Title')
+    {
+        // Note that an ancestor constructor will call $this->setSource() which will call
+        // setSource() in this class which throw an exception if $source is not a DataList
+        parent::__construct($name, $title, $source, $value);
+        $this->setLabelField($labelField);
+        $this->addExtraClass('ss-searchable-dropdown-field');
+        $this->setIsMultiple(true);
+        $this->setIsClearable(true);
+    }
+}
diff --git a/tests/php/Forms/FormFieldTest.php b/tests/php/Forms/FormFieldTest.php
index 70bf0c515cf..07d6c126884 100644
--- a/tests/php/Forms/FormFieldTest.php
+++ b/tests/php/Forms/FormFieldTest.php
@@ -36,6 +36,8 @@
 use SilverStripe\Security\Permission;
 use SilverStripe\Security\PermissionCheckboxSetField;
 use SilverStripe\Security\PermissionCheckboxSetField_Readonly;
+use SilverStripe\Forms\SearchableMultiDropdownField;
+use SilverStripe\Forms\SearchableDropdownField;
 
 class FormFieldTest extends SapphireTest
 {
@@ -554,6 +556,10 @@ public function testValidationExtensionHooksAreCalledOnFormFieldSubclasses()
                 case GridState::class:
                     $args = [GridField::create('GF')];
                     break;
+                case SearchableDropdownField::class:
+                case SearchableMultiDropdownField::class:
+                    $args = ['Test', 'Test', Group::get()];
+                    break;
                 //
                 // Fields from other modules included in the kitchensink recipe
                 //
diff --git a/tests/php/Forms/SearchableDropdownTraitTest.php b/tests/php/Forms/SearchableDropdownTraitTest.php
new file mode 100644
index 00000000000..1e8c677aae2
--- /dev/null
+++ b/tests/php/Forms/SearchableDropdownTraitTest.php
@@ -0,0 +1,219 @@
+<?php
+
+namespace SilverStripe\Forms\Tests;
+
+use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Forms\FieldList;
+use SilverStripe\Forms\SearchableDropdownField;
+use SilverStripe\Forms\Tests\FormTest\Team;
+use SilverStripe\Forms\SearchableMultiDropdownField;
+use SilverStripe\Forms\FormField;
+use SilverStripe\ORM\Search\SearchContext;
+use SilverStripe\Security\SecurityToken;
+use SilverStripe\Forms\HiddenField;
+use stdClass;
+use SilverStripe\Forms\Form;
+
+class SearchableDropdownTraitTest extends SapphireTest
+{
+    protected static $fixture_file = 'SearchableDropdownTraitTest.yml';
+
+    protected static $extra_dataobjects = [
+        Team::class,
+    ];
+
+    public function testGetSchemaDataType(): void
+    {
+        $singleField = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $multiField = new SearchableMultiDropdownField('MyField', 'MyField', Team::get());
+        $this->assertSame($singleField->getSchemaDataType(), FormField::SCHEMA_DATA_TYPE_SINGLESELECT);
+        $this->assertSame($multiField->getSchemaDataType(), FormField::SCHEMA_DATA_TYPE_MULTISELECT);
+    }
+
+    public function testSearch(): void
+    {
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $request = new HTTPRequest('GET', 'someurl', ['term' => 'Team']);
+        $request->addHeader('X-SecurityID', SecurityToken::getSecurityID());
+        $response = $field->search($request);
+        $this->assertSame(200, $response->getStatusCode());
+        $actual = json_decode($response->getBody(), true);
+        $ids = Team::get()->column('ID');
+        $names = Team::get()->column('Name');
+        $expected = [
+            ['value' => $ids[0], 'label' => $names[0]],
+            ['value' => $ids[1], 'label' => $names[1]],
+            ['value' => $ids[2], 'label' => $names[2]],
+        ];
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testSearchNoCsrfToken(): void
+    {
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $request = new HTTPRequest('GET', 'someurl', ['term' => 'Team']);
+        $response = $field->search($request);
+        $this->assertSame(400, $response->getStatusCode());
+        $actual = json_decode($response->getBody(), true);
+        $expected = ['message' => 'Invalid CSRF token'];
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testPlaceholder(): void
+    {
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $this->assertSame('Select or type to search...', $field->getPlaceholder());
+        $field->setIsSearchable(false);
+        $this->assertSame('Select...', $field->getPlaceholder());
+        $field->setIsLazyLoaded(true);
+        $this->assertSame('Type to search...', $field->getPlaceholder());
+        $field->setEmptyString('My empty string');
+        $this->assertSame('My empty string', $field->getPlaceholder());
+        $field->setPlaceholder('My placeholder');
+        $this->assertSame('My placeholder', $field->getPlaceholder());
+    }
+
+    public function testSeachContext(): void
+    {
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $team = Team::get()->first();
+        // assert fallback is the default search context
+        $this->assertSame(
+            $team->getDefaultSearchContext()->getFields()->dataFieldNames(),
+            $field->getSearchContext()->getFields()->dataFieldNames()
+        );
+        // assert setting a custom search context should override the default
+        $searchContext = new SearchContext(Team::class, new FieldList(new HiddenField('lorem')));
+        $field->setSearchContext($searchContext);
+        $this->assertSame(
+            $searchContext->getFields()->dataFieldNames(),
+            $field->getSearchContext()->getFields()->dataFieldNames()
+        );
+    }
+
+    public function testLabelField(): void
+    {
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        // will use the default value of 'Title' for label field
+        $this->assertSame('Title', $field->getLabelField());
+        // can override the default
+        $field->setLabelField('Something');
+        $this->assertSame('Something', $field->getLabelField());
+    }
+
+    /**
+     * @dataProvider provideGetValueArray
+     */
+    public function testGetValueArray(mixed $value, string|array $expected): void
+    {
+        if ($value === '<DataListValue>') {
+            $value = Team::get();
+            $ids = Team::get()->column('ID');
+            $expected = [$ids[0], $ids[1], $ids[2]];
+        } elseif ($value === '<DataObjectValue>') {
+            $value = Team::get()->first();
+            $expected = [$value->ID];
+        }
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $field->setValue($value);
+        $this->assertSame($expected, $field->getValueArray());
+    }
+
+    public function provideGetValueArray(): array
+    {
+        return [
+            'empty' => [
+                'value' => '',
+                'expected' => [],
+            ],
+            'array single form builder' => [
+                'value' => ['label' => 'MyTitle15', 'value' => '10', 'selected' => false],
+                'expected' => [10],
+            ],
+            'array multi form builder' => [
+                'value' => [
+                    ['label' => 'MyTitle10', 'value' => '10', 'selected' => true],
+                    ['label' => 'MyTitle15', 'value' => '15', 'selected' => false],
+                ],
+                'expected' => [10, 15],
+            ],
+            'string int' => [
+                'value' => '3',
+                'expected' => [3],
+            ],
+            'zero string' => [
+                'value' => '0',
+                'expected' => [],
+            ],
+            'datalist' => [
+                'value' => '<DataListValue>',
+                'expected' => '<DataListExpected>',
+            ],
+            'dataobject' => [
+                'value' => '<DataObjectValue>',
+                'expected' => '<DataObjectExpected>',
+            ],
+            'something else' => [
+                'value' => new stdClass(),
+                'expected' => [],
+            ],
+            'negative int' => [
+                'value' => -1,
+                'expected' => [],
+            ],
+            'negative string int' => [
+                'value' => '-1',
+                'expected' => [],
+            ],
+        ];
+    }
+
+    public function testGetSchemaDataDefaults(): void
+    {
+        // setting a form is required for Link() which is called for 'optionUrl'
+        $form = new Form();
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $field->setForm($form);
+        $team = Team::get()->first();
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertSame('MyField', $schema['name']);
+        $this->assertSame(['value' => $team->ID, 'label' => $team->Name, 'selected' => false], $schema['value']);
+        $this->assertFalse($schema['multi']);
+        $this->assertTrue(is_array($schema['options']));
+        $this->assertFalse(array_key_exists('optionUrl', $schema));
+        $this->assertFalse($schema['disabled']);
+        // lazyload changes options/optionUrl
+        $field->setIsLazyLoaded(true);
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertFalse(array_key_exists('options', $schema));
+        $this->assertSame('field/MyField/search', $schema['optionUrl']);
+        // disabled
+        $field->setReadonly(true);
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertTrue($schema['disabled']);
+        // multi field name
+        $field = new SearchableMultiDropdownField('MyField', 'MyField', Team::get());
+        $field->setForm($form);
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertSame('MyField[]', $schema['name']);
+        $this->assertTrue($schema['multi']);
+        // accessors
+        $field = new SearchableDropdownField('MyField', 'MyField', Team::get());
+        $field->setForm($form);
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertFalse($schema['lazyLoad']);
+        $this->assertFalse($schema['clearable']);
+        $this->assertSame('Select or type to search...', $schema['placeholder']);
+        $this->assertTrue($schema['searchable']);
+        $field->setIsLazyLoaded(true);
+        $field->setIsClearable(true);
+        $field->setPlaceholder('My placeholder');
+        $field->setIsSearchable(false);
+        $schema = $field->getSchemaDataDefaults();
+        $this->assertTrue($schema['lazyLoad']);
+        $this->assertTrue($schema['clearable']);
+        $this->assertSame('My placeholder', $schema['placeholder']);
+        $this->assertFalse($schema['searchable']);
+    }
+}
diff --git a/tests/php/Forms/SearchableDropdownTraitTest.yml b/tests/php/Forms/SearchableDropdownTraitTest.yml
new file mode 100644
index 00000000000..8ed8217342e
--- /dev/null
+++ b/tests/php/Forms/SearchableDropdownTraitTest.yml
@@ -0,0 +1,7 @@
+SilverStripe\Forms\Tests\FormTest\Team:
+  team01:
+    Name: Team 01
+  team02:
+    Name: Team 02
+  team03:
+    Name: Team 03