Cromarty Castle was a castle in Cromarty, Scotland. Cromarty, then known as Crumbathyn, was created a royal burgh in the reign of King Alexander I of Scotland. Cromarty overlooks the entrance to the Cromarty Firth and was strategically important. A motte-and-bailey castle was built in the 12th–13th century. The castle was held by Sir William de Monte Alto during the Scottish wars of independence for both the English and the Scottish.