diff --git a/.chronus/changes/deprecate-old-testing-framework-2026-6-11.md b/.chronus/changes/deprecate-old-testing-framework-2026-6-11.md
new file mode 100644
index 00000000000..fc5007c42a9
--- /dev/null
+++ b/.chronus/changes/deprecate-old-testing-framework-2026-6-11.md
@@ -0,0 +1,17 @@
+---
+changeKind: deprecation
+packages:
+  - "@typespec/compiler"
+  - "@typespec/http"
+  - "@typespec/rest"
+  - "@typespec/versioning"
+  - "@typespec/json-schema"
+  - "@typespec/xml"
+  - "@typespec/events"
+  - "@typespec/sse"
+  - "@typespec/streams"
+  - "@typespec/html-program-viewer"
+  - "@typespec/library-linter"
+---
+
+Deprecate old testing framework (`createTestHost`, `createTestRunner`, `createTestWrapper`, `createTestLibrary`, `BasicTestRunner`, `TypeSpecTestLibrary`, etc.). Use `createTester` from `@typespec/compiler/testing` instead.
diff --git a/packages/compiler/src/testing/test-host.ts b/packages/compiler/src/testing/test-host.ts
index 68ec16f523a..7eac654bd30 100644
--- a/packages/compiler/src/testing/test-host.ts
+++ b/packages/compiler/src/testing/test-host.ts
@@ -11,7 +11,7 @@ import { addTestLib, StandardTestLibrary } from "./test-compiler-host.js";
 import { createTestWrapper, resolveVirtualPath } from "./test-utils.js";
 import { BasicTestRunner, TestHost, TestHostConfig, TypeSpecTestLibrary } from "./types.js";
 
-/** Use {@link createTester} */
+/** @deprecated Use {@link createTester} */
 export async function createTestHost(config: TestHostConfig = {}): Promise<TestHost> {
   const testHost = await createTestHostInternal();
   await testHost.addTypeSpecLibrary(StandardTestLibrary);
@@ -23,7 +23,7 @@ export async function createTestHost(config: TestHostConfig = {}): Promise<TestH
   return testHost;
 }
 
-/** Use {@link createTester} */
+/** @deprecated Use {@link createTester} */
 export async function createTestRunner(host?: TestHost): Promise<BasicTestRunner> {
   const testHost = host ?? (await createTestHost());
   return createTestWrapper(testHost);
diff --git a/packages/compiler/src/testing/test-utils.ts b/packages/compiler/src/testing/test-utils.ts
index 6b34d559b97..b6c10566147 100644
--- a/packages/compiler/src/testing/test-utils.ts
+++ b/packages/compiler/src/testing/test-utils.ts
@@ -21,7 +21,9 @@ export function resolveVirtualPath(path: string, ...paths: string[]) {
   return resolvePath(rootDir, path, ...paths);
 }
 
-/** Find the package root from the provided file */
+/** Find the package root from the provided file
+ * @deprecated Use {@link createTester} instead
+ */
 export function findTestPackageRoot(fileUrl: string): Promise<string> {
   return findProjectRoot(NodeHost.stat, fileURLToPath(fileUrl)) as Promise<string>;
 }
@@ -29,6 +31,7 @@ export function findTestPackageRoot(fileUrl: string): Promise<string> {
  * Define a test library defaulting to the most common library structure.
  * @param init Library configuration.
  * @returns TypeSpec Test library.
+ * @deprecated Use {@link createTester} instead
  */
 export function createTestLibrary(init: TypeSpecTestLibraryInit): TypeSpecTestLibrary {
   const { name } = init;
@@ -53,6 +56,7 @@ export function createTestLibrary(init: TypeSpecTestLibraryInit): TypeSpecTestLi
   };
 }
 
+/** @deprecated Use {@link Tester} instead */
 export interface TestWrapperOptions {
   wrapper?: (code: string) => string;
 
@@ -68,6 +72,7 @@ export interface TestWrapperOptions {
 
   compilerOptions?: CompilerOptions;
 }
+/** @deprecated Use {@link createTester} instead */
 export function createTestWrapper(
   host: TestHost,
   testWrapperOptions: TestWrapperOptions = {},
diff --git a/packages/compiler/src/testing/types.ts b/packages/compiler/src/testing/types.ts
index 19e47db94f4..72bb9b7f5ce 100644
--- a/packages/compiler/src/testing/types.ts
+++ b/packages/compiler/src/testing/types.ts
@@ -220,6 +220,7 @@ export interface PositionedMarkerInFile extends PositionedMarker {
 // #endregion
 
 // #region Legacy Test host
+/** @deprecated Use {@link Tester} */
 export interface TestHost extends Pick<
   TestFileSystem,
   | "addTypeSpecFile"
@@ -243,12 +244,14 @@ export interface TestHost extends Pick<
   ): Promise<[Record<string, Type>, readonly Diagnostic[]]>;
 }
 
+/** @deprecated Use {@link Tester} */
 export interface TestFiles {
   realDir: string;
   pattern: string;
   virtualPath: string;
 }
 
+/** @deprecated Use {@link Tester} */
 export interface TypeSpecTestLibraryInit {
   name: string;
   packageRoot: string;
@@ -263,16 +266,19 @@ export interface TypeSpecTestLibraryInit {
   jsFileFolder?: string;
 }
 
+/** @deprecated Use {@link Tester} */
 export interface TypeSpecTestLibrary {
   name: string;
   packageRoot: string;
   files: TestFiles[];
 }
 
+/** @deprecated Use {@link Tester} */
 export interface TestHostConfig {
   libraries?: TypeSpecTestLibrary[];
 }
 
+/** @deprecated Use {@link Tester} */
 export class TestHostError extends Error {
   constructor(
     message: string,
@@ -282,6 +288,7 @@ export class TestHostError extends Error {
   }
 }
 
+/** @deprecated Use {@link TesterInstance} */
 export interface BasicTestRunner {
   readonly program: Program;
   readonly fs: Map<string, string>;
diff --git a/packages/compiler/templates/__snapshots__/emitter-ts/src/testing/index.ts b/packages/compiler/templates/__snapshots__/emitter-ts/src/testing/index.ts
deleted file mode 100644
index 2232aeb74fc..00000000000
--- a/packages/compiler/templates/__snapshots__/emitter-ts/src/testing/index.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-import { resolvePath } from "@typespec/compiler";
-import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
-import { fileURLToPath } from "url";
-
-export const EmitterTsTestLibrary: TypeSpecTestLibrary = createTestLibrary({
-  name: "emitter-ts",
-  packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../../"),
-});
diff --git a/packages/compiler/templates/__snapshots__/library-ts/src/testing/index.ts b/packages/compiler/templates/__snapshots__/library-ts/src/testing/index.ts
deleted file mode 100644
index 98f124f62a8..00000000000
--- a/packages/compiler/templates/__snapshots__/library-ts/src/testing/index.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-import { resolvePath } from "@typespec/compiler";
-import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
-import { fileURLToPath } from "url";
-
-export const LibraryTsTestLibrary: TypeSpecTestLibrary = createTestLibrary({
-  name: "library-ts",
-  packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../../"),
-});
diff --git a/packages/compiler/templates/emitter-ts/src/testing/index.ts.mu b/packages/compiler/templates/emitter-ts/src/testing/index.ts.mu
deleted file mode 100644
index cd1a7daa546..00000000000
--- a/packages/compiler/templates/emitter-ts/src/testing/index.ts.mu
+++ /dev/null
@@ -1,8 +0,0 @@
-import { resolvePath } from "@typespec/compiler";
-import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
-import { fileURLToPath } from "url";
-
-export const {{#casing.pascalCase}}{{name}}{{/casing.pascalCase}}TestLibrary: TypeSpecTestLibrary = createTestLibrary({
-  name: "{{name}}",
-  packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../../"),
-});
diff --git a/packages/compiler/templates/library-ts/src/testing/index.ts.mu b/packages/compiler/templates/library-ts/src/testing/index.ts.mu
deleted file mode 100644
index cd1a7daa546..00000000000
--- a/packages/compiler/templates/library-ts/src/testing/index.ts.mu
+++ /dev/null
@@ -1,8 +0,0 @@
-import { resolvePath } from "@typespec/compiler";
-import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
-import { fileURLToPath } from "url";
-
-export const {{#casing.pascalCase}}{{name}}{{/casing.pascalCase}}TestLibrary: TypeSpecTestLibrary = createTestLibrary({
-  name: "{{name}}",
-  packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../../"),
-});
diff --git a/packages/compiler/templates/scaffolding.json b/packages/compiler/templates/scaffolding.json
index 152f071f8f6..08823490a52 100644
--- a/packages/compiler/templates/scaffolding.json
+++ b/packages/compiler/templates/scaffolding.json
@@ -124,10 +124,6 @@
         "path": "library-ts/src/rules/no-interfaces.rule.ts",
         "destination": "src/rules/no-interfaces.rule.ts"
       },
-      {
-        "path": "library-ts/src/testing/index.ts.mu",
-        "destination": "src/testing/index.ts"
-      },
       {
         "path": "library-ts/test/decorators.test.ts.mu",
         "destination": "test/decorators.test.ts"
@@ -185,10 +181,6 @@
         "path": "emitter-ts/src/lib.ts",
         "destination": "src/lib.ts"
       },
-      {
-        "path": "emitter-ts/src/testing/index.ts.mu",
-        "destination": "src/testing/index.ts"
-      },
       {
         "path": "emitter-ts/test/hello.test.ts",
         "destination": "test/hello.test.ts"
diff --git a/packages/emitter-framework/src/testing/index.ts b/packages/emitter-framework/src/testing/index.ts
index 36a7e71dff4..43822ba4096 100644
--- a/packages/emitter-framework/src/testing/index.ts
+++ b/packages/emitter-framework/src/testing/index.ts
@@ -2,6 +2,7 @@ import { resolvePath } from "@typespec/compiler";
 import { createTestLibrary, type TypeSpecTestLibrary } from "@typespec/compiler/testing";
 import { fileURLToPath } from "url";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const EmitterFrameworkTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/emitter-framework",
   packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../"),
diff --git a/packages/events/src/testing/index.ts b/packages/events/src/testing/index.ts
index 66ba1a1bc01..aaa31876d46 100644
--- a/packages/events/src/testing/index.ts
+++ b/packages/events/src/testing/index.ts
@@ -1,5 +1,6 @@
 import { createTestLibrary, findTestPackageRoot } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const EventsTestLibrary = createTestLibrary({
   name: "@typespec/events",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/html-program-viewer/src/testing/index.ts b/packages/html-program-viewer/src/testing/index.ts
index 3054fa4f14e..9e1d12d8a22 100644
--- a/packages/html-program-viewer/src/testing/index.ts
+++ b/packages/html-program-viewer/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   type TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const ProgramViewerTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/html-program-viewer",
   jsFileFolder: "dist/emitter",
diff --git a/packages/http-client-js/src/testing/index.ts b/packages/http-client-js/src/testing/index.ts
index 5148a1bba17..a9a1fc2dcc9 100644
--- a/packages/http-client-js/src/testing/index.ts
+++ b/packages/http-client-js/src/testing/index.ts
@@ -2,6 +2,7 @@ import { resolvePath } from "@typespec/compiler";
 import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
 import { fileURLToPath } from "url";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const HttpClientJavascriptEmitterTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/http-client-js",
   packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../"),
diff --git a/packages/http-client/src/testing/index.ts b/packages/http-client/src/testing/index.ts
index fca24204afe..8cdea7d5c7a 100644
--- a/packages/http-client/src/testing/index.ts
+++ b/packages/http-client/src/testing/index.ts
@@ -2,6 +2,7 @@ import { resolvePath } from "@typespec/compiler";
 import { createTestLibrary, TypeSpecTestLibrary } from "@typespec/compiler/testing";
 import { fileURLToPath } from "url";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const HttpClientTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/http-client",
   packageRoot: resolvePath(fileURLToPath(import.meta.url), "../../../../"),
diff --git a/packages/http-server-js/src/testing/index.ts b/packages/http-server-js/src/testing/index.ts
index 94286cbfc2d..72b647b9710 100644
--- a/packages/http-server-js/src/testing/index.ts
+++ b/packages/http-server-js/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   findTestPackageRoot,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const HttpServerJavaScriptTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/http-server-js",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/http/src/testing/index.ts b/packages/http/src/testing/index.ts
index 9c1a1d327c7..75581119a16 100644
--- a/packages/http/src/testing/index.ts
+++ b/packages/http/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const HttpTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/http",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/json-schema/src/testing/index.ts b/packages/json-schema/src/testing/index.ts
index 78267d60957..ae5d09a50a2 100644
--- a/packages/json-schema/src/testing/index.ts
+++ b/packages/json-schema/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   type TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const JsonSchemaTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/json-schema",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/library-linter/src/testing/index.ts b/packages/library-linter/src/testing/index.ts
index 15db03ddbda..a8f40118510 100644
--- a/packages/library-linter/src/testing/index.ts
+++ b/packages/library-linter/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const LibraryLinterTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/library-linter",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/rest/src/testing/index.ts b/packages/rest/src/testing/index.ts
index 07fc1e57e28..967c5bf782f 100644
--- a/packages/rest/src/testing/index.ts
+++ b/packages/rest/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const RestTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/rest",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/sse/src/testing/index.ts b/packages/sse/src/testing/index.ts
index aaced1410b3..4548bdc1fab 100644
--- a/packages/sse/src/testing/index.ts
+++ b/packages/sse/src/testing/index.ts
@@ -1,5 +1,6 @@
 import { createTestLibrary, findTestPackageRoot } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const SSETestLibrary = createTestLibrary({
   name: "@typespec/sse",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/streams/src/testing/index.ts b/packages/streams/src/testing/index.ts
index 1308ba5390f..21eab67545a 100644
--- a/packages/streams/src/testing/index.ts
+++ b/packages/streams/src/testing/index.ts
@@ -1,5 +1,6 @@
 import { createTestLibrary, findTestPackageRoot } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const StreamsTestLibrary = createTestLibrary({
   name: "@typespec/streams",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/versioning/src/testing/index.ts b/packages/versioning/src/testing/index.ts
index 75fe32643a6..7f598c91102 100644
--- a/packages/versioning/src/testing/index.ts
+++ b/packages/versioning/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   type TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const VersioningTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/versioning",
   packageRoot: await findTestPackageRoot(import.meta.url),
diff --git a/packages/xml/src/testing/index.ts b/packages/xml/src/testing/index.ts
index 6f4e37bebb8..b96de17aacb 100644
--- a/packages/xml/src/testing/index.ts
+++ b/packages/xml/src/testing/index.ts
@@ -4,6 +4,7 @@ import {
   type TypeSpecTestLibrary,
 } from "@typespec/compiler/testing";
 
+/** @deprecated Use `createTester` from `@typespec/compiler/testing` instead */
 export const XmlTestLibrary: TypeSpecTestLibrary = createTestLibrary({
   name: "@typespec/xml",
   packageRoot: await findTestPackageRoot(import.meta.url),