diff --git a/.changeset/two-poets-vanish.md b/.changeset/two-poets-vanish.md
new file mode 100644
index 000000000..796fe4c7d
--- /dev/null
+++ b/.changeset/two-poets-vanish.md
@@ -0,0 +1,5 @@
+---
+'@hono/ajv-validator': patch
+---
+
+Add Ajv validator middleware
diff --git a/.github/workflows/ci-ajv-validator.yml b/.github/workflows/ci-ajv-validator.yml
new file mode 100644
index 000000000..46ef330e8
--- /dev/null
+++ b/.github/workflows/ci-ajv-validator.yml
@@ -0,0 +1,25 @@
+name: ci-ajv-validator
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'packages/ajv-validator/**'
+  pull_request:
+    branches: ['*']
+    paths:
+      - 'packages/ajv-validator/**'
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./packages/ajv-validator
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20.x
+      - run: yarn install --frozen-lockfile
+      - run: yarn build
+      - run: yarn test
diff --git a/package.json b/package.json
index f57a51c23..989faadfe 100644
--- a/package.json
+++ b/package.json
@@ -38,6 +38,7 @@
     "build:effect-validator": "yarn workspace @hono/effect-validator build",
     "build:conform-validator": "yarn workspace @hono/conform-validator build",
     "build:casbin": "yarn workspace @hono/casbin build",
+    "build:ajv-validator": "yarn workspace @hono/ajv-validator build",
     "build": "run-p 'build:*'",
     "lint": "eslint 'packages/**/*.{ts,tsx}'",
     "lint:fix": "eslint --fix 'packages/**/*.{ts,tsx}'",
diff --git a/packages/ajv-validator/README.md b/packages/ajv-validator/README.md
new file mode 100644
index 000000000..cd02581f5
--- /dev/null
+++ b/packages/ajv-validator/README.md
@@ -0,0 +1,63 @@
+# Ajv validator middleware for Hono
+
+Validator middleware using [Ajv](https://github.com/ajv-validator/ajv) for [Hono](https://honojs.dev) applications.
+Define your schema with Ajv and validate incoming requests.
+
+## Usage
+
+No Hook:
+
+```ts
+import { type JSONSchemaType } from 'ajv';
+import { ajvValidator } from '@hono/ajv-validator';
+ 
+const schema: JSONSchemaType<{ name: string; age: number }> = {
+  type: 'object',
+  properties: {
+    name: { type: 'string' },
+    age: { type: 'number' },
+  },
+  required: ['name', 'age'],
+  additionalProperties: false,
+} as const;
+
+const route = app.post('/user', ajvValidator('json', schema), (c) => {
+  const user = c.req.valid('json');
+  return c.json({ success: true, message: `${user.name} is ${user.age}` });
+});
+```
+
+Hook:
+
+```ts
+import { type JSONSchemaType } from 'ajv';
+import { ajvValidator } from '@hono/ajv-validator';
+
+const schema: JSONSchemaType<{ name: string; age: number }> = {
+  type: 'object',
+  properties: {
+    name: { type: 'string' },
+    age: { type: 'number' },
+  },
+  required: ['name', 'age'],
+  additionalProperties: false,
+};
+
+app.post(
+  '/user',
+  ajvValidator('json', schema, (result, c) => {
+    if (!result.success) {
+      return c.text('Invalid!', 400);
+    }
+  })
+  //...
+);
+```
+
+## Author
+
+Illia Khvost <https://github.com/ikhvost>
+
+## License
+
+MIT
diff --git a/packages/ajv-validator/package.json b/packages/ajv-validator/package.json
new file mode 100644
index 000000000..c2ca4be9a
--- /dev/null
+++ b/packages/ajv-validator/package.json
@@ -0,0 +1,49 @@
+{
+  "name": "@hono/ajv-validator",
+  "version": "0.0.0",
+  "description": "Validator middleware using Ajv",
+  "type": "module",
+  "module": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "test": "vitest --run",
+    "build": "tsup ./src/index.ts --format esm,cjs --dts",
+    "publint": "publint",
+    "release": "yarn build && yarn test && yarn publint && yarn publish"
+  },
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.ts",
+        "default": "./dist/index.js"
+      },
+      "require": {
+        "types": "./dist/index.d.cts",
+        "default": "./dist/index.cjs"
+      }
+    }
+  },
+  "license": "MIT",
+  "publishConfig": {
+    "registry": "https://registry.npmjs.org",
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/honojs/middleware.git"
+  },
+  "homepage": "https://github.com/honojs/middleware",
+  "peerDependencies": {
+    "ajv": ">=8.12.0",
+    "hono": ">=3.9.0"
+  },
+  "devDependencies": {
+    "ajv": ">=8.12.0",
+    "hono": "^4.4.12",
+    "tsup": "^8.1.0",
+    "vitest": "^1.6.0"
+  }
+}
diff --git a/packages/ajv-validator/src/index.ts b/packages/ajv-validator/src/index.ts
new file mode 100644
index 000000000..0e8cc8e97
--- /dev/null
+++ b/packages/ajv-validator/src/index.ts
@@ -0,0 +1,106 @@
+import type { Context, Env, MiddlewareHandler, ValidationTargets } from 'hono';
+import { validator } from 'hono/validator';
+import { Ajv, type JSONSchemaType, type ErrorObject } from 'ajv';
+
+type Hook<T, E extends Env, P extends string> = (
+  result: { success: true; data: T } | { success: false; errors: ErrorObject[] },
+  c: Context<E, P>
+) => Response | Promise<Response> | void;
+
+/**
+ * Hono middleware that validates incoming data via an Ajv JSON schema.
+ *
+ * ---
+ *
+ * No Hook
+ *
+ * ```ts
+ * import { type JSONSchemaType } from 'ajv';
+ * import { ajvValidator } from '@hono/ajv-validator';
+ *
+ * const schema: JSONSchemaType<{ name: string; age: number }> = {
+ *   type: 'object',
+ *   properties: {
+ *     name: { type: 'string' },
+ *     age: { type: 'number' },
+ *   },
+ *   required: ['name', 'age'],
+ *   additionalProperties: false,
+ * };
+ *
+ * const route = app.post('/user', ajvValidator('json', schema), (c) => {
+ *   const user = c.req.valid('json');
+ *   return c.json({ success: true, message: `${user.name} is ${user.age}` });
+ * });
+ * ```
+ *
+ * ---
+ * Hook
+ *
+ * ```ts
+ * import { type JSONSchemaType } from 'ajv';
+ * import { ajvValidator } from '@hono/ajv-validator';
+ *
+ * const schema: JSONSchemaType<{ name: string; age: number }> = {
+ *   type: 'object',
+ *   properties: {
+ *     name: { type: 'string' },
+ *     age: { type: 'number' },
+ *   },
+ *   required: ['name', 'age'],
+ *   additionalProperties: false,
+ * };
+ *
+ * app.post(
+ *   '/user',
+ *   ajvValidator('json', schema, (result, c) => {
+ *     if (!result.success) {
+ *       return c.text('Invalid!', 400);
+ *     }
+ *   })
+ *   //...
+ * );
+ * ```
+ */
+export function ajvValidator<
+  T,
+  Target extends keyof ValidationTargets,
+  E extends Env = Env,
+  P extends string = string
+>(
+  target: Target,
+  schema: JSONSchemaType<T>,
+  hook?: Hook<T, E, P>
+): MiddlewareHandler<
+  E,
+  P,
+  {
+    in: { [K in Target]: T };
+    out: { [K in Target]: T };
+  }
+> {
+  const ajv = new Ajv();
+  const validate = ajv.compile(schema);
+
+  return validator(target, (data, c) => {
+    const valid = validate(data);
+    if (valid) {
+      if (hook) {
+        const hookResult = hook({ success: true, data: data as T }, c);
+        if (hookResult instanceof Response || hookResult instanceof Promise) {
+          return hookResult;
+        }
+      }
+      return data as T;
+    }
+
+    const errors = validate.errors || [];
+    if (hook) {
+      const hookResult = hook({ success: false, errors }, c);
+      if (hookResult instanceof Response || hookResult instanceof Promise) {
+        return hookResult;
+      }
+    }
+    return c.json({ success: false, errors }, 400);
+  });
+}
diff --git a/packages/ajv-validator/test/index.test.ts b/packages/ajv-validator/test/index.test.ts
new file mode 100644
index 000000000..2cc71ffc2
--- /dev/null
+++ b/packages/ajv-validator/test/index.test.ts
@@ -0,0 +1,200 @@
+import { Hono } from 'hono';
+import type { Equal, Expect } from 'hono/utils/types';
+import { ajvValidator } from '../src';
+import { JSONSchemaType, type ErrorObject } from 'ajv';
+
+type ExtractSchema<T> = T extends Hono<infer _, infer S> ? S : never;
+
+describe('Basic', () => {
+  const app = new Hono();
+
+  const schema: JSONSchemaType<{ name: string; age: number }> = {
+    type: 'object',
+    properties: {
+      name: { type: 'string' },
+      age: { type: 'number' },
+    },
+    required: ['name', 'age'],
+    additionalProperties: false,
+  };
+
+  const route = app.post('/author', ajvValidator('json', schema), (c) => {
+    const data = c.req.valid('json');
+    return c.json({
+      success: true,
+      message: `${data.name} is ${data.age}`,
+    });
+  });
+
+  type Actual = ExtractSchema<typeof route>;
+  type Expected = {
+    '/author': {
+      $post: {
+        input: {
+          json: {
+            name: string;
+            age: number;
+          };
+        };
+        output: {
+          success: boolean;
+          message: string;
+        };
+      };
+    };
+  };
+
+  type verify = Expect<Equal<Expected, Actual>>;
+
+  it('Should return 200 response', async () => {
+    const req = new Request('http://localhost/author', {
+      body: JSON.stringify({
+        name: 'Superman',
+        age: 20,
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+    const res = await app.request(req);
+    expect(res).not.toBeNull();
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({
+      success: true,
+      message: 'Superman is 20',
+    });
+  });
+
+  it('Should return 400 response', async () => {
+    const req = new Request('http://localhost/author', {
+      body: JSON.stringify({
+        name: 'Superman',
+        age: '20',
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+    const res = await app.request(req);
+    expect(res).not.toBeNull();
+    expect(res.status).toBe(400);
+    const data = (await res.json()) as { success: boolean };
+    expect(data.success).toBe(false);
+  });
+});
+
+describe('With Hook', () => {
+  const app = new Hono();
+
+  const schema: JSONSchemaType<{ id: number; title: string }> = {
+    type: 'object',
+    properties: {
+      id: { type: 'number' },
+      title: { type: 'string' },
+    },
+    required: ['id', 'title'],
+    additionalProperties: false,
+  };
+
+  app
+    .post(
+      '/post',
+      ajvValidator('json', schema, (result, c) => {
+        if (!result.success) {
+          return c.text('Invalid!', 400);
+        }
+        const data = result.data;
+        return c.text(`${data.id} is valid!`);
+      }),
+      (c) => {
+        const data = c.req.valid('json');
+        return c.json({
+          success: true,
+          message: `${data.id} is ${data.title}`,
+        });
+      }
+    )
+    .post(
+      '/errorTest',
+      ajvValidator('json', schema, (result, c) => {
+        return c.json(result, 400);
+      }),
+      (c) => {
+        const data = c.req.valid('json');
+        return c.json({
+          success: true,
+          message: `${data.id} is ${data.title}`,
+        });
+      }
+    );
+
+  it('Should return 200 response', async () => {
+    const req = new Request('http://localhost/post', {
+      body: JSON.stringify({
+        id: 123,
+        title: 'Hello',
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+    const res = await app.request(req);
+    expect(res).not.toBeNull();
+    expect(res.status).toBe(200);
+    expect(await res.text()).toBe('123 is valid!');
+  });
+
+  it('Should return 400 response', async () => {
+    const req = new Request('http://localhost/post', {
+      body: JSON.stringify({
+        id: '123',
+        title: 'Hello',
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+    const res = await app.request(req);
+    expect(res).not.toBeNull();
+    expect(res.status).toBe(400);
+  });
+
+  it('Should return 400 response and error array', async () => {
+    const req = new Request('http://localhost/errorTest', {
+      body: JSON.stringify({
+        id: 123,
+      }),
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+    const res = await app.request(req);
+    expect(res).not.toBeNull();
+    expect(res.status).toBe(400);
+
+    const { errors, success } = (await res.json()) as {
+      success: boolean;
+      errors: ErrorObject[];
+    };
+    expect(success).toBe(false);
+    expect(Array.isArray(errors)).toBe(true);
+    expect(
+      errors.map((e: ErrorObject) => ({
+        keyword: e.keyword,
+        instancePath: e.instancePath,
+        message: e.message,
+      }))
+    ).toEqual([
+      {
+        keyword: 'required',
+        instancePath: '',
+        message: "must have required property 'title'",
+      },
+    ]);
+  });
+});
diff --git a/packages/ajv-validator/tsconfig.json b/packages/ajv-validator/tsconfig.json
new file mode 100644
index 000000000..acfcd8430
--- /dev/null
+++ b/packages/ajv-validator/tsconfig.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "./src",
+    "outDir": "./dist",
+  },
+  "include": [
+    "src/**/*.ts"
+  ],
+}
\ No newline at end of file
diff --git a/packages/ajv-validator/vitest.config.ts b/packages/ajv-validator/vitest.config.ts
new file mode 100644
index 000000000..17b54e485
--- /dev/null
+++ b/packages/ajv-validator/vitest.config.ts
@@ -0,0 +1,8 @@
+/// <reference types="vitest" />
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    globals: true,
+  },
+})
diff --git a/yarn.lock b/yarn.lock
index da7c9ee4e..8b66811c3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2407,6 +2407,20 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@hono/ajv-validator@workspace:packages/ajv-validator":
+  version: 0.0.0-use.local
+  resolution: "@hono/ajv-validator@workspace:packages/ajv-validator"
+  dependencies:
+    ajv: "npm:>=8.12.0"
+    hono: "npm:^4.4.12"
+    tsup: "npm:^8.1.0"
+    vitest: "npm:^1.6.0"
+  peerDependencies:
+    ajv: ">=8.12.0"
+    hono: ">=3.9.0"
+  languageName: unknown
+  linkType: soft
+
 "@hono/arktype-validator@workspace:packages/arktype-validator":
   version: 0.0.0-use.local
   resolution: "@hono/arktype-validator@workspace:packages/arktype-validator"
@@ -6119,6 +6133,18 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ajv@npm:>=8.12.0":
+  version: 8.17.1
+  resolution: "ajv@npm:8.17.1"
+  dependencies:
+    fast-deep-equal: "npm:^3.1.3"
+    fast-uri: "npm:^3.0.1"
+    json-schema-traverse: "npm:^1.0.0"
+    require-from-string: "npm:^2.0.2"
+  checksum: ec3ba10a573c6b60f94639ffc53526275917a2df6810e4ab5a6b959d87459f9ef3f00d5e7865b82677cb7d21590355b34da14d1d0b9c32d75f95a187e76fff35
+  languageName: node
+  linkType: hard
+
 "ajv@npm:^6.12.4, ajv@npm:^6.12.6":
   version: 6.12.6
   resolution: "ajv@npm:6.12.6"
@@ -10191,6 +10217,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"fast-uri@npm:^3.0.1":
+  version: 3.0.3
+  resolution: "fast-uri@npm:3.0.3"
+  checksum: 4b2c5ce681a062425eae4f15cdc8fc151fd310b2f69b1f96680677820a8b49c3cd6e80661a406e19d50f0c40a3f8bffdd458791baf66f4a879d80be28e10a320
+  languageName: node
+  linkType: hard
+
 "fast-url-parser@npm:^1.1.3":
   version: 1.1.3
   resolution: "fast-url-parser@npm:1.1.3"