William Addison Riner (June 26, 1878 – November 20, 1955) was a justice of the Wyoming Supreme Court from January 10, 1928, to November 20, 1955.^[1]

Born in Greene, Iowa, Riner practiced law in Michigan for less than a year before moving to Cheyenne, Wyoming in 1902.^[1] He was an active Republican Party member, and served as a city attorney, United States District Attorney, and district court judge.^[1] Riner was appointed to the Wyoming Supreme Court on January 10, 1928, by Governor Frank C. Emerson, to fill the vacancy caused by the death of Justice Charles N. Potter.^[1] Riner was then elected to the court, and re-elected in succeeding years, serving until his death.^[1]