Barry O'Neil (September 24, 1865 – March 23, 1918) was a film director and writer. His real name was Thomas J. McCarthy. He directed several Thanhouser films including the production company's first two-reeler, . He went on to work for Lubin and then World Film Corporation. He was born in New York City. O'Neil married actress Nellie Walters. In 1913 O'Neil was elected to The Lambs as a non-resident member. He died of apoplexy.