William James Frederick Riordan CBE (8 February 1908 – 15 January 1973) was an Australian politician and Minister for the Navy.
Riordan was born in Chillagoe, Queensland, son of Jim Riordan (a member of the Queensland Legislative Council from 1917 to 1923) and nephew of Darby Riordan (member for Kennedy from 1929 to 1936) and Ernest Riordan (a member of the Legislative Assembly of Queensland from 1936).
He was educated at state schools at Chillagoe, Mareeba and Gordonvale and at Brisbane Grammar School.
He worked in the Queensland Department of Justice and then became secretary to his father when he was appointed to the Industrial Court of Queensland in 1933.