diff --git a/src/Mixins/Expectation.php b/src/Mixins/Expectation.php
index 926200a8..4522155e 100644
--- a/src/Mixins/Expectation.php
+++ b/src/Mixins/Expectation.php
@@ -1142,6 +1142,22 @@ final class Expectation
         return $this;
     }
 
+    /**
+     * Asserts that the value is a ULID.
+     *
+     * @return self<TValue>
+     */
+    public function toBeUlid(string $message = ''): self
+    {
+        if (! is_string($this->value)) {
+            InvalidExpectationValue::expected('string');
+        }
+
+        Assert::assertTrue(Str::isUlid($this->value), $message);
+
+        return $this;
+    }
+
     /**
      * Asserts that the value is between 2 specified values
      *
diff --git a/src/Support/Str.php b/src/Support/Str.php
index 04f4b1fd..85ba4115 100644
--- a/src/Support/Str.php
+++ b/src/Support/Str.php
@@ -98,6 +98,14 @@ final class Str
         return preg_match('/^[\da-f]{8}-[\da-f]{4}-[\da-f]{4}-[\da-f]{4}-[\da-f]{12}$/iD', $value) > 0;
     }
 
+    /**
+     * Determine if a given value is a valid ULID.
+     */
+    public static function isUlid(string $value): bool
+    {
+        return preg_match('/^[0-9A-HJKMNP-TV-Z]{26}$/', $value) > 0;
+    }
+
     /**
      * Creates a describe block as `$describeDescription` → `$testDescription` format.
      *
diff --git a/tests/Features/Expect/toBeUlid.php b/tests/Features/Expect/toBeUlid.php
new file mode 100644
index 00000000..0f4a0e67
--- /dev/null
+++ b/tests/Features/Expect/toBeUlid.php
@@ -0,0 +1,26 @@
+<?php
+
+use Pest\Exceptions\InvalidExpectationValue;
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('failures with wrong type', function () {
+    expect([])->toBeUlid();
+})->throws(InvalidExpectationValue::class, 'Invalid expectation value type. Expected [string].');
+
+test('pass', function () {
+    expect('01ARZ3NDEKTSV4RRFFQ69G5FAV')->toBeUlid();
+    expect('01BX5ZZKBKACTAV9WEVGEMMVRE')->toBeUlid();
+    expect('7ZZZZZZZZZ0000000000000000')->toBeUlid();
+});
+
+test('failures', function () {
+    expect('foo')->toBeUlid();
+})->throws(ExpectationFailedException::class);
+
+test('failures with message', function () {
+    expect('bar')->toBeUlid('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('foo')->not->toBeUlid();
+});