diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05399e20bd..00bbe2ceec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -54,9 +54,10 @@ This section is for maintaining a changelog for all breaking changes for the cli
 - Add an integration test that runs on JDK-8 ([#795](https://github.com/opensearch-project/opensearch-java/pull/795))
 
 ### Deprecated
-- Deprecated "_toQuery()" in Query and QueryVariant ([#760](https://github.com/opensearch-project/opensearch-java/pull/760)
+- Deprecated "_toQuery()" in Query and QueryVariant ([#760](https://github.com/opensearch-project/opensearch-java/pull/760))
 
 ### Removed
+- Removed unsupported `prefix` field from CompletionSuggester ([#812](https://github.com/opensearch-project/opensearch-java/pull/812))
 
 ### Fixed
 - Fix partial success results for msearch_template ([#709](https://github.com/opensearch-project/opensearch-java/pull/709))
diff --git a/java-client/src/main/java/org/opensearch/client/opensearch/core/search/CompletionSuggester.java b/java-client/src/main/java/org/opensearch/client/opensearch/core/search/CompletionSuggester.java
index 42a7ba1280..8bba13b7f9 100644
--- a/java-client/src/main/java/org/opensearch/client/opensearch/core/search/CompletionSuggester.java
+++ b/java-client/src/main/java/org/opensearch/client/opensearch/core/search/CompletionSuggester.java
@@ -54,9 +54,6 @@ public class CompletionSuggester extends SuggesterBase implements FieldSuggester
     @Nullable
     private final SuggestFuzziness fuzzy;
 
-    @Nullable
-    private final String prefix;
-
     @Nullable
     private final String regex;
 
@@ -70,7 +67,6 @@ private CompletionSuggester(Builder builder) {
 
         this.contexts = ApiTypeHelper.unmodifiable(builder.contexts);
         this.fuzzy = builder.fuzzy;
-        this.prefix = builder.prefix;
         this.regex = builder.regex;
         this.skipDuplicates = builder.skipDuplicates;
 
@@ -103,14 +99,6 @@ public final SuggestFuzziness fuzzy() {
         return this.fuzzy;
     }
 
-    /**
-     * API name: {@code prefix}
-     */
-    @Nullable
-    public final String prefix() {
-        return this.prefix;
-    }
-
     /**
      * API name: {@code regex}
      */
@@ -152,11 +140,6 @@ protected void serializeInternal(JsonGenerator generator, JsonpMapper mapper) {
             generator.writeKey("fuzzy");
             this.fuzzy.serialize(generator, mapper);
 
-        }
-        if (this.prefix != null) {
-            generator.writeKey("prefix");
-            generator.write(this.prefix);
-
         }
         if (this.regex != null) {
             generator.writeKey("regex");
@@ -184,9 +167,6 @@ public static class Builder extends SuggesterBase.AbstractBuilder<Builder> imple
         @Nullable
         private SuggestFuzziness fuzzy;
 
-        @Nullable
-        private String prefix;
-
         @Nullable
         private String regex;
 
@@ -228,14 +208,6 @@ public final Builder fuzzy(Function<SuggestFuzziness.Builder, ObjectBuilder<Sugg
             return this.fuzzy(fn.apply(new SuggestFuzziness.Builder()).build());
         }
 
-        /**
-         * API name: {@code prefix}
-         */
-        public final Builder prefix(@Nullable String value) {
-            this.prefix = value;
-            return this;
-        }
-
         /**
          * API name: {@code regex}
          */
@@ -288,7 +260,6 @@ protected static void setupCompletionSuggesterDeserializer(ObjectDeserializer<Co
             "contexts"
         );
         op.add(Builder::fuzzy, SuggestFuzziness._DESERIALIZER, "fuzzy");
-        op.add(Builder::prefix, JsonpDeserializer.stringDeserializer(), "prefix");
         op.add(Builder::regex, JsonpDeserializer.stringDeserializer(), "regex");
         op.add(Builder::skipDuplicates, JsonpDeserializer.booleanDeserializer(), "skip_duplicates");