Robert Marion McKenna is an American lawyer and politician who served as the 17th attorney general of Washington from 2005 to 2013 after serving on the Metropolitan King County Council from 1996 to 2005. A member of the Republican Party, he ran for Governor of Washington in 2012, losing to Democrat Jay Inslee.

The attorney general of Washington is the chief legal officer of the U.S. state of Washington and head of the Washington State Office of the Attorney General. The attorney general represents clients of the state and defends the public interest in accordance to state law. The office of the attorney general is an executive office elected by the citizens of Washington, and the officeholder serves a four-year term.