diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
index ab15af74c3c..0d3668e6703 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
@@ -782,16 +782,30 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
                 }
             }
         }
+
+        List<CodegenProperty> oneOfsList = Optional.ofNullable(cm.getComposedSchemas())
+                .map(CodegenComposedSchemas::getOneOf)
+                .orElse(Collections.emptyList());
+
+        cm.oneOfModels = oneOfsList.stream()
+                .filter(CodegenProperty::getIsModel)
+                .map(CodegenProperty::getBaseType)
+                .filter(Objects::nonNull)
+                .collect(Collectors.toCollection(TreeSet::new));
+
+        cm.oneOfArrays = oneOfsList.stream()
+                .filter(CodegenProperty::getIsArray)
+                .map(CodegenProperty::getComplexType)
+                .filter(Objects::nonNull)
+                .collect(Collectors.toCollection(TreeSet::new));
+
         if (!cm.oneOf.isEmpty()) {
             // For oneOfs only import $refs within the oneOf
-            TreeSet<String> oneOfRefs = new TreeSet<>();
-            for (String im : cm.imports) {
-                if (cm.oneOf.contains(im)) {
-                    oneOfRefs.add(im);
-                }
-            }
-            cm.imports = oneOfRefs;
+            cm.imports = cm.imports.stream()
+                    .filter(im -> cm.oneOfModels.contains(im) || cm.oneOfArrays.contains(im))
+                    .collect(Collectors.toCollection(TreeSet::new));
         }
+
         return cm;
     }
 
@@ -1474,6 +1488,12 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
     public class ExtendedCodegenModel extends CodegenModel {
         @Getter @Setter
         public Set<String> modelImports = new TreeSet<String>();
+
+        @Getter @Setter
+        public Set<String> oneOfModels = new TreeSet<>();
+        @Getter @Setter
+        public Set<String> oneOfArrays = new TreeSet<>();
+
         public boolean isEntity; // Is a model containing an "id" property marked as isUniqueId
         public String returnPassthrough;
         public boolean hasReturnPassthroughVoid;
@@ -1570,6 +1590,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
             this.setItems(cm.getItems());
             this.setAdditionalProperties(cm.getAdditionalProperties());
             this.setIsModel(cm.getIsModel());
+            this.setComposedSchemas(cm.getComposedSchemas());
         }
 
         @Override
diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
index b516da670e1..721f0fc7b76 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
@@ -1,5 +1,5 @@
 {{#hasImports}}
-{{#oneOf}}
+{{#imports}}
 import type { {{{.}}} } from './{{.}}{{importFileExtension}}';
 import {
     instanceOf{{{.}}},
@@ -7,7 +7,7 @@ import {
     {{{.}}}FromJSONTyped,
     {{{.}}}ToJSON,
 } from './{{.}}{{importFileExtension}}';
-{{/oneOf}}
+{{/imports}}
 
 {{/hasImports}}
 {{>modelOneOfInterfaces}}
@@ -31,11 +31,30 @@ export function {{classname}}FromJSONTyped(json: any, ignoreDiscriminator: boole
     }
 {{/discriminator}}
 {{^discriminator}}
-    {{#oneOf}}
+    {{#oneOfModels}}
+    {{#-first}}
+    if (typeof json !== 'object') {
+        return json;
+    }
+    {{/-first}}
     if (instanceOf{{{.}}}(json)) {
         return {{{.}}}FromJSONTyped(json, true);
     }
-    {{/oneOf}}
+    {{/oneOfModels}}
+    {{#oneOfArrays}}
+    {{#-first}}
+    if (Array.isArray(json)) {
+        if (json.every(item => typeof item === 'object')) {
+    {{/-first}}
+            if (json.every(item => instanceOf{{{.}}}(item))) {
+                return json.map(value => {{{.}}}FromJSONTyped(value, true));
+            }
+    {{#-last}}
+        }
+        return json;
+    }
+    {{/-last}}
+    {{/oneOfArrays}}
 
     return {} as any;
 {{/discriminator}}
@@ -59,13 +78,31 @@ export function {{classname}}ToJSONTyped(value?: {{classname}} | null, ignoreDis
             return json;
     }
 {{/discriminator}}
-
 {{^discriminator}}
-    {{#oneOf}}
+    {{#oneOfModels}}
+    {{#-first}}
+    if (typeof value !== 'object') {
+        return value;
+    }
+    {{/-first}}
     if (instanceOf{{{.}}}(value)) {
         return {{{.}}}ToJSON(value as {{{.}}});
     }
-    {{/oneOf}}
+    {{/oneOfModels}}
+    {{#oneOfArrays}}
+    {{#-first}}
+    if (Array.isArray(value)) {
+        if (value.every(item => typeof item === 'object')) {
+    {{/-first}}
+            if (value.every(item => instanceOf{{{.}}}(item))) {
+                return value.map(value => {{{.}}}ToJSON(value as {{{.}}}));
+            }
+    {{#-last}}
+        }
+        return value;
+    }
+    {{/-last}}
+    {{/oneOfArrays}}
 
     return {};
 {{/discriminator}}
diff --git a/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/oneOf.yaml b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/oneOf.yaml
index 244139a28d3..ba0dd51d792 100644
--- a/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/oneOf.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/oneOf.yaml
@@ -15,12 +15,34 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/TestResponse'
+  /test-array:
+    get:
+      operationId: testArray
+      responses:
+        200:
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/TestArrayResponse'
 components:
   schemas:
+    TestArrayResponse:
+      oneOf:
+        - type: array
+          items:
+            $ref: "#/components/schemas/TestA"
+        - type: array
+          items:
+            $ref: "#/components/schemas/TestB"
+        - type: array
+          items:
+            type: string
     TestResponse:
       oneOf:
         - $ref: "#/components/schemas/TestA"
         - $ref: "#/components/schemas/TestB"
+        - type: string
     TestA:
       type: object
       properties:
@@ -34,4 +56,4 @@ components:
         bar:
           type: string
       required:
-        - bar
+        - bar
\ No newline at end of file
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/.openapi-generator/FILES b/samples/client/petstore/typescript-fetch/builds/oneOf/.openapi-generator/FILES
index 1e29c70aeda..6bb15a3adfc 100644
--- a/samples/client/petstore/typescript-fetch/builds/oneOf/.openapi-generator/FILES
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/.openapi-generator/FILES
@@ -2,6 +2,7 @@ apis/DefaultApi.ts
 apis/index.ts
 index.ts
 models/TestA.ts
+models/TestArrayResponse.ts
 models/TestB.ts
 models/TestResponse.ts
 models/index.ts
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/apis/DefaultApi.ts b/samples/client/petstore/typescript-fetch/builds/oneOf/apis/DefaultApi.ts
index 3383adf93df..f7e1936ab80 100644
--- a/samples/client/petstore/typescript-fetch/builds/oneOf/apis/DefaultApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/apis/DefaultApi.ts
@@ -15,9 +15,12 @@
 
 import * as runtime from '../runtime';
 import type {
+  TestArrayResponse,
   TestResponse,
 } from '../models/index';
 import {
+    TestArrayResponseFromJSON,
+    TestArrayResponseToJSON,
     TestResponseFromJSON,
     TestResponseToJSON,
 } from '../models/index';
@@ -51,4 +54,28 @@ export class DefaultApi extends runtime.BaseAPI {
         return await response.value();
     }
 
+    /**
+     */
+    async testArrayRaw(initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<runtime.ApiResponse<TestArrayResponse>> {
+        const queryParameters: any = {};
+
+        const headerParameters: runtime.HTTPHeaders = {};
+
+        const response = await this.request({
+            path: `/test-array`,
+            method: 'GET',
+            headers: headerParameters,
+            query: queryParameters,
+        }, initOverrides);
+
+        return new runtime.JSONApiResponse(response, (jsonValue) => TestArrayResponseFromJSON(jsonValue));
+    }
+
+    /**
+     */
+    async testArray(initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<TestArrayResponse> {
+        const response = await this.testArrayRaw(initOverrides);
+        return await response.value();
+    }
+
 }
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestArrayResponse.ts b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestArrayResponse.ts
new file mode 100644
index 00000000000..0848d99781c
--- /dev/null
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestArrayResponse.ts
@@ -0,0 +1,82 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * testing oneOf without discriminator
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import type { TestA } from './TestA';
+import {
+    instanceOfTestA,
+    TestAFromJSON,
+    TestAFromJSONTyped,
+    TestAToJSON,
+} from './TestA';
+import type { TestB } from './TestB';
+import {
+    instanceOfTestB,
+    TestBFromJSON,
+    TestBFromJSONTyped,
+    TestBToJSON,
+} from './TestB';
+
+/**
+ * @type TestArrayResponse
+ * 
+ * @export
+ */
+export type TestArrayResponse = Array<TestA> | Array<TestB> | Array<string>;
+
+export function TestArrayResponseFromJSON(json: any): TestArrayResponse {
+    return TestArrayResponseFromJSONTyped(json, false);
+}
+
+export function TestArrayResponseFromJSONTyped(json: any, ignoreDiscriminator: boolean): TestArrayResponse {
+    if (json == null) {
+        return json;
+    }
+    if (Array.isArray(json)) {
+        if (json.every(item => typeof item === 'object')) {
+            if (json.every(item => instanceOfTestA(item))) {
+                return json.map(value => TestAFromJSONTyped(value, true));
+            }
+            if (json.every(item => instanceOfTestB(item))) {
+                return json.map(value => TestBFromJSONTyped(value, true));
+            }
+        }
+        return json;
+    }
+
+    return {} as any;
+}
+
+export function TestArrayResponseToJSON(json: any): any {
+    return TestArrayResponseToJSONTyped(json, false);
+}
+
+export function TestArrayResponseToJSONTyped(value?: TestArrayResponse | null, ignoreDiscriminator: boolean = false): any {
+    if (value == null) {
+        return value;
+    }
+    if (Array.isArray(value)) {
+        if (value.every(item => typeof item === 'object')) {
+            if (value.every(item => instanceOfTestA(item))) {
+                return value.map(value => TestAToJSON(value as TestA));
+            }
+            if (value.every(item => instanceOfTestB(item))) {
+                return value.map(value => TestBToJSON(value as TestB));
+            }
+        }
+        return value;
+    }
+
+    return {};
+}
+
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestResponse.ts b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestResponse.ts
index e228a3e9f73..09d1da13156 100644
--- a/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestResponse.ts
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestResponse.ts
@@ -32,7 +32,7 @@ import {
  * 
  * @export
  */
-export type TestResponse = TestA | TestB;
+export type TestResponse = TestA | TestB | string;
 
 export function TestResponseFromJSON(json: any): TestResponse {
     return TestResponseFromJSONTyped(json, false);
@@ -42,6 +42,9 @@ export function TestResponseFromJSONTyped(json: any, ignoreDiscriminator: boolea
     if (json == null) {
         return json;
     }
+    if (typeof json !== 'object') {
+        return json;
+    }
     if (instanceOfTestA(json)) {
         return TestAFromJSONTyped(json, true);
     }
@@ -60,7 +63,9 @@ export function TestResponseToJSONTyped(value?: TestResponse | null, ignoreDiscr
     if (value == null) {
         return value;
     }
-
+    if (typeof value !== 'object') {
+        return value;
+    }
     if (instanceOfTestA(value)) {
         return TestAToJSON(value as TestA);
     }
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/models/index.ts b/samples/client/petstore/typescript-fetch/builds/oneOf/models/index.ts
index 8da6963476f..7ba8efbbf0e 100644
--- a/samples/client/petstore/typescript-fetch/builds/oneOf/models/index.ts
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/models/index.ts
@@ -1,5 +1,6 @@
 /* tslint:disable */
 /* eslint-disable */
 export * from './TestA';
+export * from './TestArrayResponse';
 export * from './TestB';
 export * from './TestResponse';