diff --git a/.changeset/yellow-bees-float.md b/.changeset/yellow-bees-float.md
new file mode 100644
index 00000000000..dd7884e999b
--- /dev/null
+++ b/.changeset/yellow-bees-float.md
@@ -0,0 +1,6 @@
+---
+"@typespec/compiler": minor
+---
+
+@chronus/chronus
+Added `$.type.listUnder()` utility function to allow listing all types under a container (namespace/interface) that match a filter criteria.
\ No newline at end of file
diff --git a/packages/compiler/src/core/helpers/type-utils.ts b/packages/compiler/src/core/helpers/type-utils.ts
new file mode 100644
index 00000000000..6db664260a4
--- /dev/null
+++ b/packages/compiler/src/core/helpers/type-utils.ts
@@ -0,0 +1,115 @@
+import { Interface, Namespace, Type } from "../types.js";
+import { isTemplateDeclaration } from "../type-utils.js";
+
+/**
+ * List types under the given container. Will list types recursively.
+ * @param container Container.
+ * @param filter Function to filter types.
+ */
+export function listTypesUnder<T extends Type = Type>(
+  container: Namespace | Interface,
+  filter: (type: Type) => type is T,
+): T[];
+
+/**
+ * List types under the given container. Will list types recursively.
+ * @param container Container.
+ * @param filter Function to filter types.
+ */
+export function listTypesUnder(
+  container: Namespace | Interface,
+  filter: (type: Type) => boolean,
+): Type[];
+
+export function listTypesUnder(
+  container: Namespace | Interface,
+  filter: (type: Type) => boolean,
+): Type[] {
+  const types: Type[] = [];
+
+  function addTypes(current: Namespace | Interface) {
+    if (isTemplateDeclaration(current)) {
+      // Skip template types
+      return;
+    }
+
+    // For interfaces, we only have operations
+    if (current.kind === "Interface") {
+      for (const op of current.operations.values()) {
+        if (filter(op)) {
+          types.push(op);
+        }
+      }
+      return;
+    }
+
+    // For namespaces, check all contained type collections
+    const namespace = current;
+
+    // Check models
+    for (const model of namespace.models.values()) {
+      if (filter(model)) {
+        types.push(model);
+      }
+    }
+
+    // Check operations
+    for (const op of namespace.operations.values()) {
+      if (filter(op)) {
+        types.push(op);
+      }
+    }
+
+    // Check scalars
+    for (const scalar of namespace.scalars.values()) {
+      if (filter(scalar)) {
+        types.push(scalar);
+      }
+    }
+
+    // Check enums
+    for (const enumType of namespace.enums.values()) {
+      if (filter(enumType)) {
+        types.push(enumType);
+      }
+    }
+
+    // Check unions
+    for (const union of namespace.unions.values()) {
+      if (filter(union)) {
+        types.push(union);
+      }
+    }
+
+    // Check interfaces
+    for (const iface of namespace.interfaces.values()) {
+      if (filter(iface)) {
+        types.push(iface);
+      }
+    }
+
+    // Recursively check sub-namespaces
+    for (const subNamespace of namespace.namespaces.values()) {
+      if (
+        !(
+          subNamespace.name === "Prototypes" &&
+          subNamespace.namespace?.name === "TypeSpec" &&
+          subNamespace.namespace.namespace?.name === ""
+        )
+      ) {
+        if (filter(subNamespace)) {
+          types.push(subNamespace);
+        }
+        addTypes(subNamespace);
+      }
+    }
+
+    // Recursively check operations in interfaces
+    for (const iface of namespace.interfaces.values()) {
+      addTypes(iface);
+    }
+  }
+
+  addTypes(container);
+  return types;
+}
\ No newline at end of file
diff --git a/packages/compiler/src/typekit/kits/type.ts b/packages/compiler/src/typekit/kits/type.ts
index 14ec7d759c9..b2e1135f082 100644
--- a/packages/compiler/src/typekit/kits/type.ts
+++ b/packages/compiler/src/typekit/kits/type.ts
@@ -1,4 +1,5 @@
 import { getLocationContext } from "../../core/helpers/location-context.js";
+import { listTypesUnder } from "../../core/helpers/type-utils.js";
 import {
   getMaxItems,
   getMaxLength,
@@ -13,6 +14,7 @@ import { isNeverType } from "../../core/type-utils.js";
 import {
   Entity,
   Enum,
+  Interface,
   Model,
   Namespace,
   Node,
@@ -164,6 +166,28 @@ export interface TypeTypekit {
       kind?: K,
     ) => K extends Type["kind"] ? Extract<Type, { kind: K }> : undefined
   >;
+
+  /**
+   * List all types under the given container that satisfy the filter criteria.
+   * @param container The container to inspect.
+   * @param filter A filter function to select specific types.
+   * @returns An array of types that match the filter criteria.
+   */
+  listUnder<T extends Type = Type>(
+    container: Namespace | Interface,
+    filter: (type: Type) => type is T,
+  ): T[];
+
+  /**
+   * List all types under the given container that satisfy the filter criteria.
+   * @param container The container to inspect.
+   * @param filter A filter function to select specific types.
+   * @returns An array of types that match the filter criteria.
+   */
+  listUnder(
+    container: Namespace | Interface,
+    filter: (type: Type) => boolean,
+  ): Type[];
 }
 
 interface TypekitExtension {
@@ -345,5 +369,8 @@ defineKit<TypekitExtension>({
       }
       return [type, diagnostics];
     }),
+    listUnder(container, filter) {
+      return listTypesUnder(container, filter);
+    },
   },
 });
diff --git a/packages/compiler/test/core/helpers/type-utils.test.ts b/packages/compiler/test/core/helpers/type-utils.test.ts
new file mode 100644
index 00000000000..69d8e96f679
--- /dev/null
+++ b/packages/compiler/test/core/helpers/type-utils.test.ts
@@ -0,0 +1,75 @@
+import { Interface, Model, Namespace, Operation } from "../../../src/core/types.js";
+import { createTestHost, TestHost } from "../../../src/testing/index.js";
+import { listTypesUnder } from "../../../src/core/helpers/type-utils.js";
+
+let host: TestHost;
+
+beforeEach(async () => {
+  host = await createTestHost();
+});
+
+it("lists all types in a namespace", async () => {
+  const testCode = `
+    namespace A {
+      model M1 {}
+      model M2 {}
+    }
+  `;
+
+  const { A } = (await host.compile(testCode)) as { A: Namespace };
+  const types = listTypesUnder(A, (t) => true);
+  
+  // Should include 2 models plus namespace A
+  expect(types.length).toBe(3);
+});
+
+it("filters models", async () => {
+  const testCode = `
+    namespace A {
+      model M1 {}
+      model M2 {}
+      scalar S {}
+    }
+  `;
+
+  const { A } = (await host.compile(testCode)) as { A: Namespace };
+  const models = listTypesUnder(A, (t): t is Model => t.kind === "Model");
+  
+  expect(models.length).toBe(2);
+  expect(models.every(m => m.kind === "Model")).toBe(true);
+});
+
+it("handles nested namespaces", async () => {
+  const testCode = `
+    namespace A {
+      model M1 {}
+      
+      namespace B {
+        model M2 {}
+      }
+    }
+  `;
+
+  const { A } = (await host.compile(testCode)) as { A: Namespace };
+  const models = listTypesUnder(A, (t): t is Model => t.kind === "Model");
+  
+  expect(models.length).toBe(2);
+});
+
+it("handles interfaces and operations", async () => {
+  const testCode = `
+    namespace A {
+      interface I1 {
+        op1(): void;
+        op2(): string;
+      }
+    }
+  `;
+
+  const { A } = (await host.compile(testCode)) as { A: Namespace };
+  const operations = listTypesUnder(A, (t): t is Operation => t.kind === "Operation");
+  const interfaces = listTypesUnder(A, (t): t is Interface => t.kind === "Interface");
+  
+  expect(operations.length).toBe(2);
+  expect(interfaces.length).toBe(1);
+});
\ No newline at end of file
diff --git a/packages/compiler/test/typekit/type.test.ts b/packages/compiler/test/typekit/type.test.ts
index 46c422de864..bf3a57e1fda 100644
--- a/packages/compiler/test/typekit/type.test.ts
+++ b/packages/compiler/test/typekit/type.test.ts
@@ -4,6 +4,7 @@ import { isTemplateInstance } from "../../src/index.js";
 import { expectDiagnosticEmpty, expectDiagnostics } from "../../src/testing/expect.js";
 import { $ } from "../../src/typekit/index.js";
 import { getAssignables, getTypes } from "./utils.js";
+import { TestHost, createTestHost } from "../../src/testing/index.js";
 
 describe("is", () => {
   it("checks if an entity is a type", async () => {
@@ -667,3 +668,94 @@ describe("resolve", () => {
     });
   });
 });
+
+describe("listUnder", () => {
+  let host: TestHost;
+
+  beforeEach(async () => {
+    host = await createTestHost();
+  });
+
+  it("lists all types under a namespace", async () => {
+    const testCode = `
+      namespace A {
+        model M1 {}
+        model M2 {}
+        
+        @doc("Some doc")
+        model M3 {}
+      }
+    `;
+
+    const { A } = (await host.compile(testCode)) as { A: Namespace };
+    const types = host.program.typespecType.listUnder(A, t => true);
+    
+    // Should include all 3 models plus the namespace itself when filter is 'true'
+    expect(types.length).toBe(4);
+  });
+
+  it("filters types with the provided filter function", async () => {
+    const testCode = `
+      namespace A {
+        model M1 {}
+        
+        @doc("Some doc")
+        model M2 {}
+        
+        @deprecated
+        model M3 {}
+      }
+    `;
+
+    const { A } = (await host.compile(testCode)) as { A: Namespace };
+    
+    // Filter only models with @doc decorator
+    const types = host.program.typespecType.listUnder(A, t => {
+      return t.kind === "Model" && !!t.decorators.find(d => d.decorator.name === "@doc");
+    });
+    
+    expect(types.length).toBe(1);
+    expect((types[0] as Model).name).toBe("M2");
+  });
+  
+  it("recursively searches sub-namespaces", async () => {
+    const testCode = `
+      namespace A {
+        model M1 {}
+        
+        namespace B {
+          model M2 {}
+          
+          namespace C {
+            model M3 {}
+          }
+        }
+      }
+    `;
+
+    const { A } = (await host.compile(testCode)) as { A: Namespace };
+    
+    // Should find all models in all namespaces
+    const types = host.program.typespecType.listUnder(A, t => t.kind === "Model");
+    
+    expect(types.length).toBe(3);
+  });
+  
+  it("finds operations in interfaces", async () => {
+    const testCode = `
+      namespace A {
+        interface I1 {
+          op1(): void;
+          op2(): string;
+        }
+      }
+    `;
+
+    const { A } = (await host.compile(testCode)) as { A: Namespace };
+    
+    // Should find both operations
+    const types = host.program.typespecType.listUnder(A, t => t.kind === "Operation");
+    
+    expect(types.length).toBe(2);
+  });
+});