Byron Barr (August 18, 1917 – November 3, 1966), sometimes billed as Byron S. Barr, was an American actor. He appeared in 19 films from 1944 to 1951.

Barr perhaps is best known for his role as Nino Zachetti in Double Indemnity, his first appearance. He also had a role in films like Love Letters, Pitfall, Down Dakota Way, They Made Me a Killer, and The File on Thelma Jordon. His only lead role came in the 1946 B-movie Tokyo Rose. Barr retired from acting in 1951. He died on November 3, 1966, in Sacramento County, California, of unknown causes at age 49.