diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
index 0743275db62a..a4e1bc131f2d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
@@ -1423,6 +1423,10 @@ public void postProcessParameter(CodegenParameter parameter) {
     @Override
     public void postProcessModelProperty(CodegenModel model, CodegenProperty property) {
         postProcessPattern(property.pattern, property.vendorExtensions);
+
+        if (property.isArray) {
+            postProcessPattern(property.items.pattern, property.items.vendorExtensions);
+        }
     }
 
     /*
diff --git a/modules/openapi-generator/src/main/resources/python-fastapi/model_generic.mustache b/modules/openapi-generator/src/main/resources/python-fastapi/model_generic.mustache
index e5e64a08ebeb..2b59898b9a55 100644
--- a/modules/openapi-generator/src/main/resources/python-fastapi/model_generic.mustache
+++ b/modules/openapi-generator/src/main/resources/python-fastapi/model_generic.mustache
@@ -50,6 +50,36 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
             raise ValueError(r"must validate the regular expression {{{vendorExtensions.x-pattern}}}")
         return value
     {{/vendorExtensions.x-regex}}
+    {{#isArray}}
+    {{#items}}
+    {{#vendorExtensions.x-regex}}
+
+    @field_validator('{{{name}}}')
+    def {{{name}}}_items_validate_regular_expression(cls, value):
+        """Validates the regular expression"""
+        {{^required}}
+        if value is None:
+            return value
+        {{/required}}
+        {{#required}}
+        {{#isNullable}}
+        if value is None:
+            return value
+        {{/isNullable}}
+        {{/required}}
+
+        for item in value:
+        {{#isNullable}}
+            if item is None:
+                continue
+
+        {{/isNullable}}
+            if not re.match(r"{{{.}}}", item{{#vendorExtensions.x-modifiers}} ,re.{{{.}}}{{/vendorExtensions.x-modifiers}}):
+                raise ValueError(r"must validate the regular expression {{{vendorExtensions.x-pattern}}}")
+        return value
+    {{/vendorExtensions.x-regex}}
+    {{/items}}
+    {{/isArray}}
     {{#isEnum}}
 
     @field_validator('{{{name}}}')
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
index 33b9d46555c5..931d6cd41ce2 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
@@ -71,4 +71,22 @@ public void testNoAdditionalSlashesInQueryRegex() throws IOException {
         TestUtils.assertFileContains(Paths.get(output + "/src/openapi_server/apis/default_api.py"),
                 "r\"^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$\"");
     }
+
+    @Test
+    public void testRegexPatternCheckedForArrayItems() throws IOException {
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("python-fastapi")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"))
+                .setInputSpec("src/test/resources/3_1/issue_23102.yaml");
+
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        TestUtils.assertFileContains(Paths.get(output + "/src/openapi_server/models/test_object.py"),
+                "raise ValueError(r\"must validate the regular expression /^[A-Z0-9_\\- ]+$/\")");
+    }
 }
diff --git a/modules/openapi-generator/src/test/resources/3_1/issue_23102.yaml b/modules/openapi-generator/src/test/resources/3_1/issue_23102.yaml
new file mode 100644
index 000000000000..f0f51f0607ac
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_1/issue_23102.yaml
@@ -0,0 +1,26 @@
+openapi: 3.1.0
+info:
+  title: List items regex test
+  version: 0.0.1
+paths:
+  /test:
+    get:
+      responses:
+        "200":
+          description: test
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/TestObject"
+components:
+  schemas:
+    TestObject:
+      properties:
+        tags:
+          items:
+            pattern: "/^[A-Z0-9_\\- ]+$/"
+            type:
+              oneOf:
+                - string
+                - type: "null"
+          type: array
\ No newline at end of file