Richard Anthony Lanahan (September 27, 1911 – March 12, 1975) was an American professional baseball pitcher. He played in Major League Baseball (MLB) for the Pittsburgh Pirates and Washington Senators in a four-year career varying from 1935 to 1941.
Lanahan's best season was the 1940 season in which he had six wins in 40 games, and a 4.25 earned run average. His forty games played was ninth in the National League.