Mary Willoughby was a ship of the Royal Navy. She was appears in the navy lists from 1535, during the reign of Henry VIII. She was named after Maria Willoughby, a lady-in-waiting and close friend of Catherine of Aragon. The ship was taken by the Scots in 1536 and joined the Royal Scots Navy, The English recaptured her in 1547. The ship was rebuilt in 1551, increasing in size from 140 bm to 160 bm.