Leon Francis Riley Sr. (August 20, 1906 – September 13, 1970) was an American professional baseball player who became a manager in the minor leagues.

During a playing career that stretched from 1927 to 1942 and 1944 to 1949, Riley appeared in 2,267 minor league games for 21 different teams, with a brief trial with the 1944 Philadelphia Phillies during the World War II manpower shortage.

Born in Princeton, Nebraska, Riley was an outfielder and first baseman who stood 6 ft 1 in (1.85 m) (185 cm) tall, weighed 185 pounds (83.9 kg), batted left-handed, and threw right-handed.

Although he reached the top minor-league level in 116 games for the Rochester Red Wings (1932) and Baltimore Orioles (1939) of the Class AA International League, he spent most of his playing career in the Class A Western League, leading that loop in triples with 27 in 1929.

He would manage for 11 seasons (1937–38; 1940–41; 1945–51) in the minor leagues, including stints in the farm systems of the Brooklyn Dodgers and the Phillies.