diff --git a/botocore/endpoint_provider.py b/botocore/endpoint_provider.py
index 0fbd802b8d..d76f9ac245 100644
--- a/botocore/endpoint_provider.py
+++ b/botocore/endpoint_provider.py
@@ -577,6 +577,7 @@ class ParameterType(Enum):
 
     string = str
     boolean = bool
+    stringarray = tuple
 
 
 class ParameterDefinition:
@@ -600,7 +601,7 @@ def __init__(
         except AttributeError:
             raise EndpointResolutionError(
                 msg=f"Unknown parameter type: {parameter_type}. "
-                "A parameter must be of type string or boolean."
+                "A parameter must be of type string, boolean, or stringarray."
             )
         self.documentation = documentation
         self.builtin = builtIn
diff --git a/botocore/model.py b/botocore/model.py
index 70d20f8cca..efd15e90e7 100644
--- a/botocore/model.py
+++ b/botocore/model.py
@@ -624,6 +624,10 @@ def context_parameters(self):
             and 'name' in shape.metadata['contextParam']
         ]
 
+    @CachedProperty
+    def operation_context_parameters(self):
+        return self._operation_model.get('operationContextParams', [])
+
     @CachedProperty
     def request_compression(self):
         return self._operation_model.get('requestcompression')
diff --git a/botocore/regions.py b/botocore/regions.py
index 4c23737270..d3b2705727 100644
--- a/botocore/regions.py
+++ b/botocore/regions.py
@@ -22,6 +22,8 @@
 import re
 from enum import Enum
 
+import jmespath
+
 from botocore import UNSIGNED, xform_name
 from botocore.auth import AUTH_TYPE_MAPS, HAS_CRT
 from botocore.crt import CRT_SUPPORTED_AUTH_TYPES
@@ -578,6 +580,13 @@ def _resolve_param_from_context(
         )
         if dynamic is not None:
             return dynamic
+        operation_context_params = (
+            self._resolve_param_as_operation_context_param(
+                param_name, operation_model, call_args
+            )
+        )
+        if operation_context_params is not None:
+            return operation_context_params
         return self._resolve_param_as_client_context_param(param_name)
 
     def _resolve_param_as_static_context_param(
@@ -600,6 +609,14 @@ def _resolve_param_as_client_context_param(self, param_name):
             client_ctx_varname = client_ctx_params[param_name]
             return self._client_context.get(client_ctx_varname)
 
+    def _resolve_param_as_operation_context_param(
+        self, param_name, operation_model, call_args
+    ):
+        operation_ctx_params = operation_model.operation_context_parameters
+        if param_name in operation_ctx_params:
+            path = operation_ctx_params[param_name]['path']
+            return jmespath.search(path, call_args)
+
     def _resolve_param_as_builtin(self, builtin_name, builtins):
         if builtin_name not in EndpointResolverBuiltins.__members__.values():
             raise UnknownEndpointResolutionBuiltInName(name=builtin_name)
diff --git a/botocore/utils.py b/botocore/utils.py
index a54f4a39d3..2d55e8a8dc 100644
--- a/botocore/utils.py
+++ b/botocore/utils.py
@@ -1479,7 +1479,7 @@ def lru_cache_weakref(*cache_args, **cache_kwargs):
     functools implementation which offers ``max_size`` and ``typed`` properties.
 
     lru_cache is a global cache even when used on a method. The cache's
-    reference to ``self`` will prevent garbace collection of the object. This
+    reference to ``self`` will prevent garbage collection of the object. This
     wrapper around functools.lru_cache replaces the reference to ``self`` with
     a weak reference to not interfere with garbage collection.
     """
@@ -1491,6 +1491,9 @@ def func_with_weakref(weakref_to_self, *args, **kwargs):
 
         @functools.wraps(func)
         def inner(self, *args, **kwargs):
+            for kwarg_key, kwarg_value in kwargs.items():
+                if isinstance(kwarg_value, list):
+                    kwargs[kwarg_key] = tuple(kwarg_value)
             return func_with_weakref(weakref.ref(self), *args, **kwargs)
 
         inner.cache_info = func_with_weakref.cache_info
diff --git a/tests/unit/data/endpoints/test-cases/array-index.json b/tests/unit/data/endpoints/test-cases/array-index.json
new file mode 100644
index 0000000000..aa73d460d3
--- /dev/null
+++ b/tests/unit/data/endpoints/test-cases/array-index.json
@@ -0,0 +1,37 @@
+{
+  "version": "1.0",
+  "testCases": [
+    {
+      "documentation": "Access an array index at index 0",
+      "params": {
+        "ResourceList": ["resource"]
+      },
+      "expect": {
+        "endpoint": {
+          "url": "https://www.resource.example.com"
+        }
+      }
+    },
+    {
+      "documentation": "Resolved value when array is explictly set to empty",
+      "params": {
+        "ResourceList": []
+      },
+      "expect": {
+        "endpoint": {
+          "url": "https://www.example.com"
+        }
+      }
+    },
+    {
+      "documentation": "Resolved value to default if array is unset",
+      "params": {
+      },
+      "expect": {
+        "endpoint": {
+          "url": "https://www.default1.example.com"
+        }
+      }
+    }
+  ]
+}
diff --git a/tests/unit/data/endpoints/valid-rules/array-index.json b/tests/unit/data/endpoints/valid-rules/array-index.json
new file mode 100644
index 0000000000..3d426b09aa
--- /dev/null
+++ b/tests/unit/data/endpoints/valid-rules/array-index.json
@@ -0,0 +1,47 @@
+{
+  "version": "1.3",
+  "parameters": {
+    "ResourceList": {
+      "required": true,
+      "default": ["default1", "default2"],
+      "type": "stringArray"
+    }
+  },
+  "rules": [
+    {
+      "documentation": "Array is set, retrieve index 0",
+      "conditions": [
+        {
+          "fn": "isSet",
+          "argv": [
+            {
+              "ref": "ResourceList"
+            }
+          ]
+        },
+        {
+          "fn": "getAttr",
+          "argv": [
+            {
+              "ref": "ResourceList"
+            },
+            "[0]"
+          ],
+          "assign": "resourceid"
+        }
+      ],
+      "endpoint": {
+        "url": "https://www.{resourceid}.example.com"
+      },
+      "type": "endpoint"
+    },
+    {
+      "documentation": "Fallback when array is unset",
+      "conditions": [],
+      "endpoint": {
+        "url": "https://www.example.com"
+      },
+      "type": "endpoint"
+    }
+  ]
+}
diff --git a/tests/unit/test_endpoint_provider.py b/tests/unit/test_endpoint_provider.py
index 8bc8c429d0..3d6bf81e32 100644
--- a/tests/unit/test_endpoint_provider.py
+++ b/tests/unit/test_endpoint_provider.py
@@ -137,6 +137,7 @@ def endpoint_rule():
 
 def ruleset_testcases():
     filenames = [
+        "array-index",
         "aws-region",
         "default-values",
         "eventbridge",