Colonel William Butler (died 1789) was a Pennsylvania officer during the American Revolutionary War, known for his leadership in the Battle of Monmouth, the burning of the Indian villages at Unadilla and Oquaga, and in the Sullivan-Clinton Expedition.
His family emigrated from Ireland sometime before 1760 and settled in Cumberland County, Pennsylvania.
In the late 1760s he worked as a frontier fur trader near Pittsburgh with his brother Richard.
He was commissioned a lieutenant colonel in the Continental Army upon the formation of the 4th Pennsylvania Regiment on October 25, 1776.
Butler was the second of five brothers who served as officers in the American Revolution.