Karl I of Anhalt-Zerbst (17 November 1534 in Dessau – 4 May 1561 in Zerbst), was a German prince of the House of Ascania and ruler of the principality of Anhalt-Zerbst.
He was the eldest son of John V, Prince of Anhalt-Zerbst, by his wife Margaret, daughter of Joachim I Nestor, Elector of Brandenburg.