diff --git a/library/CHANGELOG.md b/library/CHANGELOG.md
index 1fdfa51f5..9c0b76803 100644
--- a/library/CHANGELOG.md
+++ b/library/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All notable changes to the library will be documented in this file.
 
+## vX.X.X (Month DD, YYYY)
+
+- Add `mac`, `mac48` and `mac64` validation function (pull request #270)
+
 ## v0.22.0 (December 03, 2023)
 
 - Add support for boolean to `notValue` validation (pull request #261)
diff --git a/library/src/regex.ts b/library/src/regex.ts
index 8ae655c5f..ecc1d4003 100644
--- a/library/src/regex.ts
+++ b/library/src/regex.ts
@@ -65,6 +65,18 @@ export const ISO_TIMESTAMP_REGEX =
  */
 export const ISO_WEEK_REGEX = /^\d{4}-W(?:0[1-9]|[1-4]\d|5[0-3])$/u;
 
+/**
+ * [MAC](https://en.wikipedia.org/wiki/MAC_address) 48 bit regex.
+ */
+export const MAC48_REGEX =
+  /^(?:[\da-f]{2}:){5}[\da-f]{2}$|^(?:[\da-f]{2}-){5}[\da-f]{2}$|^(?:[\da-f]{4}\.){2}[\da-f]{4}$/iu;
+
+/**
+ * [MAC](https://en.wikipedia.org/wiki/MAC_address) 64 bit regex.
+ */
+export const MAC64_REGEX =
+  /^(?:[\da-f]{2}:){7}[\da-f]{2}$|^(?:[\da-f]{2}-){7}[\da-f]{2}$|^(?:[\da-f]{4}\.){3}[\da-f]{4}$|^(?:[\da-f]{4}:){3}[\da-f]{4}$/iu;
+
 /**
  * [ULID](https://github.com/ulid/spec) regex.
  */
diff --git a/library/src/validations/index.ts b/library/src/validations/index.ts
index c48408deb..8e11f75af 100644
--- a/library/src/validations/index.ts
+++ b/library/src/validations/index.ts
@@ -20,6 +20,9 @@ export * from './isoTimeSecond/index.ts';
 export * from './isoTimestamp/index.ts';
 export * from './isoWeek/index.ts';
 export * from './length/index.ts';
+export * from './mac/index.ts';
+export * from './mac48/index.ts';
+export * from './mac64/index.ts';
 export * from './maxBytes/index.ts';
 export * from './maxLength/index.ts';
 export * from './maxSize/index.ts';
diff --git a/library/src/validations/mac/index.ts b/library/src/validations/mac/index.ts
new file mode 100644
index 000000000..8245c6754
--- /dev/null
+++ b/library/src/validations/mac/index.ts
@@ -0,0 +1 @@
+export * from './mac.ts';
diff --git a/library/src/validations/mac/mac.test.ts b/library/src/validations/mac/mac.test.ts
new file mode 100644
index 000000000..66597b8ae
--- /dev/null
+++ b/library/src/validations/mac/mac.test.ts
@@ -0,0 +1,45 @@
+import { describe, expect, test } from 'vitest';
+import { mac } from './mac.ts';
+
+describe('mac', () => {
+  test('should pass only MAC address', () => {
+    const validate = mac();
+
+    const value1 = 'b6:05:20:67:f9:58';
+    expect(validate._parse(value1).output).toBe(value1);
+    const value2 = 'b6-05-20-67-f9-58';
+    expect(validate._parse(value2).output).toBe(value2);
+    const value3 = 'b605.2067.f958';
+    expect(validate._parse(value3).output).toBe(value3);
+    const value4 = '00:25:96:FF:FE:12:34:56';
+    expect(validate._parse(value4).output).toBe(value4);
+    const value5 = '00-1A-2B-3C-4D-5E-6F-70';
+    expect(validate._parse(value5).output).toBe(value5);
+    const value6 = '0025.96FF.FE12.3456';
+    expect(validate._parse(value6).output).toBe(value6);
+    const value7 = '0025:96FF:FE12:3456';
+    expect(validate._parse(value7).output).toBe(value7);
+
+    expect(validate._parse('').issues).toBeTruthy();
+    expect(validate._parse('00:1G:2B:3C:4D:5E').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F:70:80').issues).toBeTruthy();
+    expect(validate._parse('b605-2067-f958').issues).toBeTruthy();
+    expect(validate._parse('00_1A_2B_3C_4D_5E').issues).toBeTruthy();
+    expect(validate._parse('001A2B3C4D5E6F').issues).toBeTruthy();
+    expect(validate._parse('ZZ:ZZ:ZZ:ZZ:ZZ:ZZ').issues).toBeTruthy();
+    expect(
+      validate._parse('00:1A:2B:3C:4D:5E:6F:70:80:90:AB').issues
+    ).toBeTruthy();
+    expect(validate._parse('001122334455').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F:70:ZZ').issues).toBeTruthy();
+    expect(validate._parse('GHIJ:KLNM:OPQR').issues).toBeTruthy();
+  });
+
+  test('should return custom error message', () => {
+    const error = 'Value is not MAC address!';
+    const validate = mac(error);
+    expect(validate._parse('test').issues?.[0].message).toBe(error);
+  });
+});
diff --git a/library/src/validations/mac/mac.ts b/library/src/validations/mac/mac.ts
new file mode 100644
index 000000000..55cd0314e
--- /dev/null
+++ b/library/src/validations/mac/mac.ts
@@ -0,0 +1,41 @@
+import { MAC48_REGEX, MAC64_REGEX } from '../../regex.ts';
+import type { BaseValidation, ErrorMessage } from '../../types/index.ts';
+import { actionIssue, actionOutput } from '../../utils/index.ts';
+
+/**
+ * MAC validation type.
+ */
+export type MacValidation<TInput extends string> = BaseValidation<TInput> & {
+  /**
+   * The validation type.
+   */
+  type: 'mac';
+  /**
+   * The MAC 48 and 64 bit regex.
+   */
+  requirement: [RegExp, RegExp];
+};
+
+/**
+ * Creates a validation function that validates a [MAC](https://en.wikipedia.org/wiki/MAC_address).
+ *
+ * @param message The error message.
+ *
+ * @returns A validation function.
+ */
+export function mac<TInput extends string>(
+  message: ErrorMessage = 'Invalid MAC'
+): MacValidation<TInput> {
+  return {
+    type: 'mac',
+    async: false,
+    message,
+    requirement: [MAC48_REGEX, MAC64_REGEX],
+    _parse(input) {
+      return !this.requirement[0].test(input) &&
+        !this.requirement[1].test(input)
+        ? actionIssue(this.type, this.message, input, this.requirement)
+        : actionOutput(input);
+    },
+  };
+}
diff --git a/library/src/validations/mac48/index.ts b/library/src/validations/mac48/index.ts
new file mode 100644
index 000000000..cec81fa18
--- /dev/null
+++ b/library/src/validations/mac48/index.ts
@@ -0,0 +1 @@
+export * from './mac48.ts';
diff --git a/library/src/validations/mac48/mac48.test.ts b/library/src/validations/mac48/mac48.test.ts
new file mode 100644
index 000000000..4c1d823c0
--- /dev/null
+++ b/library/src/validations/mac48/mac48.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, test } from 'vitest';
+import { mac48 } from './mac48.ts';
+
+describe('mac48', () => {
+  test('should pass only MAC 48 address', () => {
+    const validate = mac48();
+
+    const value1 = 'b6:05:20:67:f9:58';
+    expect(validate._parse(value1).output).toBe(value1);
+    const value2 = 'b6-05-20-67-f9-58';
+    expect(validate._parse(value2).output).toBe(value2);
+    const value3 = 'b605.2067.f958';
+    expect(validate._parse(value3).output).toBe(value3);
+
+    expect(validate._parse('').issues).toBeTruthy();
+    expect(validate._parse('00:1G:2B:3C:4D:5E').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D').issues).toBeTruthy();
+    expect(validate._parse('b605-2067-f958').issues).toBeTruthy();
+    expect(validate._parse('00_1A_2B_3C_4D_5E').issues).toBeTruthy();
+    expect(validate._parse('001A2B3C4D5E6F').issues).toBeTruthy();
+    expect(validate._parse('ZZ:ZZ:ZZ:ZZ:ZZ:ZZ').issues).toBeTruthy();
+    expect(
+      validate._parse('00:1A:2B:3C:4D:5E:6F:70:80:90:AB').issues
+    ).toBeTruthy();
+    expect(validate._parse('001122334455').issues).toBeTruthy();
+    expect(validate._parse('GHIJ:KLNM:OPQR').issues).toBeTruthy();
+  });
+
+  test('should return custom error message', () => {
+    const error = 'Value is not MAC address!';
+    const validate = mac48(error);
+    expect(validate._parse('test').issues?.[0].message).toBe(error);
+  });
+});
diff --git a/library/src/validations/mac48/mac48.ts b/library/src/validations/mac48/mac48.ts
new file mode 100644
index 000000000..ee468e933
--- /dev/null
+++ b/library/src/validations/mac48/mac48.ts
@@ -0,0 +1,40 @@
+import { MAC48_REGEX } from '../../regex.ts';
+import type { BaseValidation, ErrorMessage } from '../../types/index.ts';
+import { actionIssue, actionOutput } from '../../utils/index.ts';
+
+/**
+ * MAC validation type.
+ */
+export type Mac48Validation<TInput extends string> = BaseValidation<TInput> & {
+  /**
+   * The validation type.
+   */
+  type: 'mac48';
+  /**
+   * The 48 bit MAC regex.
+   */
+  requirement: RegExp;
+};
+
+/**
+ * Creates a validation function that validates a 48 bit [MAC](https://en.wikipedia.org/wiki/MAC_address).
+ *
+ * @param message The error message.
+ *
+ * @returns A validation function.
+ */
+export function mac48<TInput extends string>(
+  message: ErrorMessage = 'Invalid 48 bit MAC'
+): Mac48Validation<TInput> {
+  return {
+    type: 'mac48',
+    async: false,
+    message,
+    requirement: MAC48_REGEX,
+    _parse(input) {
+      return !this.requirement.test(input)
+        ? actionIssue(this.type, this.message, input, this.requirement)
+        : actionOutput(input);
+    },
+  };
+}
diff --git a/library/src/validations/mac64/index.ts b/library/src/validations/mac64/index.ts
new file mode 100644
index 000000000..6fc2732ca
--- /dev/null
+++ b/library/src/validations/mac64/index.ts
@@ -0,0 +1 @@
+export * from './mac64.ts';
diff --git a/library/src/validations/mac64/mac64.test.ts b/library/src/validations/mac64/mac64.test.ts
new file mode 100644
index 000000000..4049ab0d5
--- /dev/null
+++ b/library/src/validations/mac64/mac64.test.ts
@@ -0,0 +1,39 @@
+import { describe, expect, test } from 'vitest';
+import { mac64 } from './mac64.ts';
+
+describe('mac64', () => {
+  test('should pass only MAC address', () => {
+    const validate = mac64();
+
+    const value1 = '00:25:96:FF:FE:12:34:56';
+    expect(validate._parse(value1).output).toBe(value1);
+    const value2 = '00-1A-2B-3C-4D-5E-6F-70';
+    expect(validate._parse(value2).output).toBe(value2);
+    const value3 = '0025.96FF.FE12.3456';
+    expect(validate._parse(value3).output).toBe(value3);
+    const value4 = '0025:96FF:FE12:3456';
+    expect(validate._parse(value4).output).toBe(value4);
+
+    expect(validate._parse('').issues).toBeTruthy();
+    expect(validate._parse('00:1G:2B:3C:4D:5E').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F').issues).toBeTruthy();
+    expect(validate._parse('0025.96FF.FE12').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F:70:80').issues).toBeTruthy();
+    expect(validate._parse('b605-2067-f958').issues).toBeTruthy();
+    expect(validate._parse('00_1A_2B_3C_4D_5E').issues).toBeTruthy();
+    expect(validate._parse('001A2B3C4D5E6F').issues).toBeTruthy();
+    expect(validate._parse('ZZ:ZZ:ZZ:ZZ:ZZ:ZZ').issues).toBeTruthy();
+    expect(
+      validate._parse('00:1A:2B:3C:4D:5E:6F:70:80:90:AB').issues
+    ).toBeTruthy();
+    expect(validate._parse('001122334455').issues).toBeTruthy();
+    expect(validate._parse('00:1A:2B:3C:4D:5E:6F:70:ZZ').issues).toBeTruthy();
+    expect(validate._parse('GHIJ:KLNM:OPQR').issues).toBeTruthy();
+  });
+
+  test('should return custom error message', () => {
+    const error = 'Value is not MAC address!';
+    const validate = mac64(error);
+    expect(validate._parse('test').issues?.[0].message).toBe(error);
+  });
+});
diff --git a/library/src/validations/mac64/mac64.ts b/library/src/validations/mac64/mac64.ts
new file mode 100644
index 000000000..f74de1d8e
--- /dev/null
+++ b/library/src/validations/mac64/mac64.ts
@@ -0,0 +1,40 @@
+import { MAC64_REGEX } from '../../regex.ts';
+import type { BaseValidation, ErrorMessage } from '../../types/index.ts';
+import { actionIssue, actionOutput } from '../../utils/index.ts';
+
+/**
+ * MAC validation type.
+ */
+export type Mac64Validation<TInput extends string> = BaseValidation<TInput> & {
+  /**
+   * The validation type.
+   */
+  type: 'mac64';
+  /**
+   * The 64 bit MAC regex.
+   */
+  requirement: RegExp;
+};
+
+/**
+ * Creates a validation function that validates a 64 bit [MAC](https://en.wikipedia.org/wiki/MAC_address).
+ *
+ * @param message The error message.
+ *
+ * @returns A validation function.
+ */
+export function mac64<TInput extends string>(
+  message: ErrorMessage = 'Invalid 64 bit MAC'
+): Mac64Validation<TInput> {
+  return {
+    type: 'mac64',
+    async: false,
+    message,
+    requirement: MAC64_REGEX,
+    _parse(input) {
+      return !this.requirement.test(input)
+        ? actionIssue(this.type, this.message, input, this.requirement)
+        : actionOutput(input);
+    },
+  };
+}
diff --git a/library/tsconfig.json b/library/tsconfig.json
index 8f72398dd..797bdb8c7 100644
--- a/library/tsconfig.json
+++ b/library/tsconfig.json
@@ -9,5 +9,5 @@
     "skipLibCheck": true,
     "noEmit": true
   },
-  "include": ["src", "./*.ts"]
+  "include": ["src", "./*.config.ts"]
 }
diff --git a/website/src/routes/api/(schemas)/string/index.mdx b/website/src/routes/api/(schemas)/string/index.mdx
index 2fa8164c8..2854ee1a1 100644
--- a/website/src/routes/api/(schemas)/string/index.mdx
+++ b/website/src/routes/api/(schemas)/string/index.mdx
@@ -127,6 +127,9 @@ The following APIs can be combined with `string`.
     'isoTimestamp',
     'isoWeek',
     'length',
+    'mac',
+    'mac48',
+    'mac64',
     'maxBytes',
     'maxLength',
     'maxValue',
diff --git a/website/src/routes/api/(validations)/mac/index.mdx b/website/src/routes/api/(validations)/mac/index.mdx
new file mode 100644
index 000000000..934982acc
--- /dev/null
+++ b/website/src/routes/api/(validations)/mac/index.mdx
@@ -0,0 +1,7 @@
+---
+title: mac
+---
+
+# mac
+
+> The content of this page is not yet ready. Until then just use the [source code](https://github.com/fabian-hiller/valibot/blob/main/library/src/validations/mac/mac.ts).
diff --git a/website/src/routes/api/(validations)/mac48/index.mdx b/website/src/routes/api/(validations)/mac48/index.mdx
new file mode 100644
index 000000000..de86b4dd5
--- /dev/null
+++ b/website/src/routes/api/(validations)/mac48/index.mdx
@@ -0,0 +1,7 @@
+---
+title: mac48
+---
+
+# mac48
+
+> The content of this page is not yet ready. Until then just use the [source code](https://github.com/fabian-hiller/valibot/blob/main/library/src/validations/mac48/mac48.ts).
diff --git a/website/src/routes/api/(validations)/mac64/index.mdx b/website/src/routes/api/(validations)/mac64/index.mdx
new file mode 100644
index 000000000..e33ecfdd7
--- /dev/null
+++ b/website/src/routes/api/(validations)/mac64/index.mdx
@@ -0,0 +1,7 @@
+---
+title: mac64
+---
+
+# mac64
+
+> The content of this page is not yet ready. Until then just use the [source code](https://github.com/fabian-hiller/valibot/blob/main/library/src/validations/mac64/mac64.ts).
diff --git a/website/src/routes/api/menu.md b/website/src/routes/api/menu.md
index c948cf319..12ec3eeea 100644
--- a/website/src/routes/api/menu.md
+++ b/website/src/routes/api/menu.md
@@ -81,6 +81,9 @@
 - [isoTimestamp](/api/isoTimestamp)
 - [isoWeek](/api/isoWeek)
 - [length](/api/length)
+- [mac](/api/mac)
+- [mac48](/api/mac48)
+- [mac64](/api/mac64)
 - [maxBytes](/api/maxBytes)
 - [maxLength](/api/maxLength)
 - [maxSize](/api/maxSize)
diff --git a/website/src/routes/guides/(main-concepts)/pipelines/index.mdx b/website/src/routes/guides/(main-concepts)/pipelines/index.mdx
index a6bb6229c..e641b9768 100644
--- a/website/src/routes/guides/(main-concepts)/pipelines/index.mdx
+++ b/website/src/routes/guides/(main-concepts)/pipelines/index.mdx
@@ -62,6 +62,9 @@ Validation functions examine the input and, if the input does not meet a certain
     'isoTimestamp',
     'isoWeek',
     'length',
+    'mac',
+    'mac48',
+    'mac64',
     'maxBytes',
     'maxLength',
     'maxSize',