Don Harmon (born November 26, 1966) is a Democratic member of the Illinois Senate, representing the 39th District since 2003.
His district includes Chicago's Austin neighborhood and the suburbs of Oak Park, Addison, Bensenville, Elmwood Park, Franklin Park, Melrose Park, Northlake, River Grove, Rosemont, Schiller Park, and Stone Park.
In January 2009, incoming Senate President John Cullerton appointed Harmon Assistant Majority Leader.
Harmon was appointed Illinois Senate President Pro Tempore in 2011.
In January 2019, Harmon lost that title when Senate President John Cullerton retired the President Pro Tempore leadership position.
Harmon is now one of five Illinois Senate Assistant Majority Leaders.