diff --git a/src/Calendars/Calendar.php b/src/Calendars/Calendar.php
index 85cde2e..b7b5313 100644
--- a/src/Calendars/Calendar.php
+++ b/src/Calendars/Calendar.php
@@ -2,6 +2,7 @@
 
 namespace Nylas\Calendars;
 
+use DateTimeZone;
 use Nylas\Utilities\API;
 use Nylas\Utilities\Helper;
 use Nylas\Utilities\Options;
@@ -69,6 +70,33 @@ public function getCalendarsList(array $params = []): array
 
     // ------------------------------------------------------------------------------
 
+    /**
+     * add calendar
+     *
+     * @param array $params
+     *
+     * @return array
+     */
+    public function addCalendar(array $params): array
+    {
+        $rules = $this->addCalendarRules();
+
+        $accessToken = $this->options->getAccessToken();
+
+        V::doValidate(V::keySet(...$rules), $params);
+        V::doValidate(V::stringType()->notEmpty(), $accessToken);
+
+        $header = ['Authorization' => $accessToken];
+
+        return $this->options
+            ->getSync()
+            ->setFormParams($params)
+            ->setHeaderParams($header)
+            ->post(API::LIST['calendars']);
+    }
+
+    // ------------------------------------------------------------------------------
+
     /**
      * get calendar
      *
@@ -109,4 +137,22 @@ public function getCalendar($calendarId): array
     }
 
     // ------------------------------------------------------------------------------
+
+    /**
+     * rules for add calendar
+     *
+     * @return array
+     */
+    private function addCalendarRules(): array
+    {
+        return
+            [
+                V::key('name', V::stringType()->notEmpty()),
+                V::keyOptional('description', V::stringType()->notEmpty()),
+                V::keyOptional('location', V::stringType()->notEmpty()),
+                V::keyOptional('timezone', V::in(DateTimeZone::listIdentifiers())),
+            ];
+    }
+
+    // ------------------------------------------------------------------------------
 }
diff --git a/tests/CalendarTest.php b/tests/CalendarTest.php
index 2f37fe4..b5f1f14 100644
--- a/tests/CalendarTest.php
+++ b/tests/CalendarTest.php
@@ -40,4 +40,28 @@ public function testGetCalendar(): void
     }
 
     // ------------------------------------------------------------------------------
+
+    public function testAddCalendar(): void
+    {
+        $params = $this->getCalendarInfo();
+
+        $data = $this->client->Calendars()->Calendar()->addCalendar($params);
+
+        $this->assertArrayHasKey('id', $data);
+    }
+
+    // ------------------------------------------------------------------------------
+
+    /**
+     * @return array
+     */
+    private function getCalendarInfo(): array
+    {
+        return [
+            'name'        => 'Test Calendar',
+            'description' => 'This is a test calendar.',
+            'timezone'    => 'America/New_York',
+            'location'    => 'Front Conference Room',
+        ];
+    }
 }