diff --git a/bun.lockb b/bun.lockb
index cbaee6d06..78894db9b 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/deno_dist/middleware/timing/index.ts b/deno_dist/middleware/timing/index.ts
index d4dc022f1..429929c32 100644
--- a/deno_dist/middleware/timing/index.ts
+++ b/deno_dist/middleware/timing/index.ts
@@ -21,7 +21,7 @@ interface TimingOptions {
   enabled: boolean | ((c: Context) => boolean)
   totalDescription: string
   autoEnd: boolean
-  crossOrigin: boolean | string
+  crossOrigin: boolean | string | ((c: Context) => boolean | string)
 }
 
 const getTime = () => {
@@ -64,10 +64,14 @@ export const timing = (config?: Partial<TimingOptions>): MiddlewareHandler => {
 
     if (enabled) {
       c.res.headers.append('Server-Timing', headers.join(','))
-      if (options.crossOrigin) {
+
+      const crossOrigin =
+        typeof options.crossOrigin === 'function' ? options.crossOrigin(c) : options.crossOrigin
+
+      if (crossOrigin) {
         c.res.headers.append(
           'Timing-Allow-Origin',
-          typeof options.crossOrigin === 'string' ? options.crossOrigin : '*'
+          typeof crossOrigin === 'string' ? crossOrigin : '*'
         )
       }
     }
diff --git a/src/middleware/timing/index.test.ts b/src/middleware/timing/index.test.ts
index 079c7a18d..ae5eed34f 100644
--- a/src/middleware/timing/index.test.ts
+++ b/src/middleware/timing/index.test.ts
@@ -55,4 +55,89 @@ describe('Server-Timing API', () => {
     expect(res.headers.get('server-timing')?.includes(region)).toBeTruthy()
     expect(res.headers.get('server-timing')?.includes(regionDesc)).toBeTruthy()
   })
+
+  describe('Should handle crossOrigin setting', async () => {
+    it('Should do nothing when crossOrigin is falsy', async () => {
+      const crossOriginApp = new Hono()
+
+      crossOriginApp.use(
+        '*',
+        timing({
+          crossOrigin: false,
+        })
+      )
+
+      crossOriginApp.get('/', (c) => c.text('/'))
+
+      const res = await crossOriginApp.request('http://localhost/')
+
+      expect(res).not.toBeNull()
+      expect(res.headers.has('server-timing')).toBeTruthy()
+      expect(res.headers.has('timing-allow-origin')).toBeFalsy()
+    })
+
+    it('Should set Timing-Allow-Origin to * when crossOrigin is true', async () => {
+      const crossOriginApp = new Hono()
+
+      crossOriginApp.use(
+        '*',
+        timing({
+          crossOrigin: true,
+        })
+      )
+
+      crossOriginApp.get('/', (c) => c.text('/'))
+
+      const res = await crossOriginApp.request('http://localhost/')
+
+      expect(res).not.toBeNull()
+      expect(res.headers.has('server-timing')).toBeTruthy()
+      expect(res.headers.has('timing-allow-origin')).toBeTruthy()
+      expect(res.headers.get('timing-allow-origin')).toBe('*')
+    })
+
+    it('Should set Timing-Allow-Origin to the value of crossOrigin when it is a string', async () => {
+      const crossOriginApp = new Hono()
+
+      crossOriginApp.use(
+        '*',
+        timing({
+          crossOrigin: 'https://example.com',
+        })
+      )
+
+      crossOriginApp.get('/', (c) => c.text('/'))
+
+      const res = await crossOriginApp.request('http://localhost/')
+
+      expect(res).not.toBeNull()
+      expect(res.headers.has('server-timing')).toBeTruthy()
+      expect(res.headers.has('timing-allow-origin')).toBeTruthy()
+      expect(res.headers.get('timing-allow-origin')).toBe('https://example.com')
+    })
+
+    it('Should set Timing-Allow-Origin to the return value of crossOrigin when it is a function', async () => {
+      const crossOriginApp = new Hono()
+
+      crossOriginApp.use(
+        '*',
+        timing({
+          crossOrigin: (c) => c.req.header('origin') ?? '*',
+        })
+      )
+
+      crossOriginApp.get('/', (c) => c.text('/'))
+
+      const res = await crossOriginApp.request('http://localhost/', {
+        headers: {
+          origin: 'https://example.com',
+        },
+      })
+
+      expect(res).not.toBeNull()
+      expect(res.headers.has('server-timing')).toBeTruthy()
+      expect(res.headers.has('timing-allow-origin')).toBeTruthy()
+      expect(res.headers.get('timing-allow-origin')).toBe('https://example.com')
+    })
+  })
 })
diff --git a/src/middleware/timing/index.ts b/src/middleware/timing/index.ts
index 356d7e9c1..504331b15 100644
--- a/src/middleware/timing/index.ts
+++ b/src/middleware/timing/index.ts
@@ -21,7 +21,7 @@ interface TimingOptions {
   enabled: boolean | ((c: Context) => boolean)
   totalDescription: string
   autoEnd: boolean
-  crossOrigin: boolean | string
+  crossOrigin: boolean | string | ((c: Context) => boolean | string)
 }
 
 const getTime = () => {
@@ -64,10 +64,14 @@ export const timing = (config?: Partial<TimingOptions>): MiddlewareHandler => {
 
     if (enabled) {
       c.res.headers.append('Server-Timing', headers.join(','))
-      if (options.crossOrigin) {
+
+      const crossOrigin =
+        typeof options.crossOrigin === 'function' ? options.crossOrigin(c) : options.crossOrigin
+
+      if (crossOrigin) {
         c.res.headers.append(
           'Timing-Allow-Origin',
-          typeof options.crossOrigin === 'string' ? options.crossOrigin : '*'
+          typeof crossOrigin === 'string' ? crossOrigin : '*'
         )
       }
     }