William Hays (died 1786) was an American soldier who served in the Continental Army during the American Revolutionary War. He worked as a barber in Carlisle, Pennsylvania before marrying Mary Ludwig Hays, and he served in the 4th Pennsylvania Artillery Regiment during the war. During the June 1778 Battle of Monmouth, Hays was wounded, and his wife stepped in to help load and fire cannons, being nicknamed "Molly Pitcher". Hays survived the war and died in 1786.