William Richardson (1735–1825) was a Maryland politician and Continental Army officer. Richardson served in the Maryland Assembly from 1773–1776, introducing the bill that formed Caroline County in 1774. As Colonel of the 5th Maryland Regiment of the Maryland Line, he participated in the Battle of Harlem Heights in 1776, and later moved the Continental Treasury from Philadelphia to Baltimore in 1777. He was a delegate to the Maryland State Convention of 1788, to vote whether Maryland should ratify the proposed Constitution of the United States. He fought at the Battle of Camden in 1780. In later life he also served as a Presidential Elector.