William Thomas Rodgers, Baron Rodgers of Quarry Bank, PC (born 28 October 1928) is a British politician who served as Secretary of State for Transport from 1976 to 1979, and was one of the 'Gang of Four' of senior British Labour Party politicians who defected to form the Social Democratic Party (SDP). He subsequently helped to lead the SDP into the merger that formed the Liberal Democrats in 1988, and later served as that party's leader in the House of Lords between 1997 and 2001.