Earl of Northesk is a title in the Peerage of Scotland. It was created in 1662 for John Carnegie, who notably served as Sheriff of Forfarshire. He was given the subsidiary title of Lord Rosehill and Eglismauldie at the same time. Carnegie had already been created Earl of Ethie and Lord Lour in 1647 but relinquished those titles in exchange for the 1662 creations. For the purposes of precedence and seniority, the earldom of Northesk is treated as having been created in 1647, the date of the creation of the earldom of Ethie.

Admiral William Carnegie, 7th Earl of Northesk was a British naval officer who served during the American Revolutionary War, French Revolutionary War, and Napoleonic Wars. While in command of HMS Monmouth he was caught in the Nore Mutiny of 1797 and was the officer selected to relay the demands of the mutineers to George III. He most notably served as third-in-command of the Mediterranean Fleet at the Battle of Trafalgar in HMS Britannia. He later became Rear-Admiral of the United Kingdom and Commander-in-Chief, Plymouth.