Harry Shannon (Saginaw, Michigan, 13 de juny de 1890 - Hollywood, Los Angeles, 27 de juliol de 1964) va ser un actor de personatges nord-americà. Va aparèixer sovint a pel·lícules de l'Oest.

Born and raised on a farm in Michigan in 1890, Irish-American character actor Harry Shannon had the credentials for becoming a staple player in westerns. He started off his career traveling around with repertory and stock companies and developed his musical abilities in tent shows, burlesque houses and such tuneful Broadway shows as "Oh, Kay!" (1926), "Hold Everything" (1928), "Simple Simon" (1931), and "Pardon My English" (1933). A company member of Joseph Schildkraut's Hollywood Theater Guild, Shannon broke into films at the advent of sound and started things off in comedy film shorts opposite such celebrated players as Bert Lahr, Shemp Howard, and Leon Errol. In the 1940s Shannon established himself in feature-length movies and although he remained a minor, second-string player, he proved himself a durable presence in westerns usually remaining on the good side of the law as sheriffs and bucolic dads. In lighthearted entertainment he could be found as a friendly Irish cop or bartender. He made a slight but memorable impression as Kane's alcoholic father in the classic Citizen Kane (1941), while his last role would be as the grandfather in the musical Gypsy (1962). In between were small parts in such notable films as The Fighting Sullivans (1944), The Jolson Story (1946), High Noon (1952), Touch of Evil (1958), and The Buccaneer (1958). 1950s TV westerns such as Cheyenne (1955), Have Gun - Will Travel (1957), Rawhide (1959), and Gunsmoke (1955) made consistent use of his rustic demeanor. Shannon died in 1964 at age 74.