A nine-year member of the Norwood Board of Selectmen, Riley was appointed to the Civil Service Commission by Governor Paul A. Dever in 1951.
In 1954 and 1956, Riley was a candidate for Treasurer and Receiver-General of Massachusetts.
He lost in the Democratic primary both times to John Francis Kennedy.
In 1957, Foster Furcolo appointed him to replace Rudolph King as Registrar of Motor Vehicles.
[1] Riley was a candidate for Governor of Massachusetts in 1962; losing the Democratic nomination to Endicott Peabody.