William Kilty (1757 – October 10, 1821) was a United States federal judge.
Born in London, England, Kilty read law at the College of St. Omer to enter the bar. He also studied medicine under Edward Johnson, of Annapolis. In the American Revolutionary War, Kilty served in the 4th Maryland Regiment as a Surgeon's Mate from 1778 to 1780, and as a Surgeon from 1780 to 1783. He was appointed compiler of the Laws of Maryland from 1798 to 1800.
Kilty received a recess appointment from Thomas Jefferson on March 23, 1801, to a new seat on the United States Circuit Court of the District of Columbia created by 2 Stat. 103. Formally nominated on January 6, 1802, he was confirmed by the United States Senate on January 26, 1802, and received his commission the same day. Kilty served for a times as Chief Judge of the court. His service was terminated on January 27, 1806 upon his resignation to become Chancellor of Maryland, an office that he held from 1806 until his death in 1821, in Annapolis, Maryland.