William Augustine Washington (November 25, 1757 – October 2, 1810) was a Virginia planter and officer who served one term in the Virginia House of Delegates representing Westmoreland County, as well as terms as colonel of the county militia and as the county sheriff, before moving to the newly established District of Columbia. The son of the half-brother of President George Washington, he was also one of the seven executors of the former President's estate.