William Louis of Anhalt-Köthen (3 August 1638, in Köthen – 13 April 1665, in Köthen), was a German prince of the House of Ascania and ruler of the principality of Anhalt-Köthen.
He was the second son of Louis I, Prince of Anhalt-Köthen, but second-born son of his second wife Sophie, daughter of Simon VI, Count of Lippe.