Robert Lee Flanigan (August 22, 1926 – May 15, 2011) was an American tenor vocalist and founding member of The Four Freshmen, a jazz vocal group. The Four Freshmen originated in early 1948 when brothers Ross and Don Barbour, then at Butler University's Arthur Jordan Conservatory in Indianapolis, Indiana, formed a barbershop quartet called Hal's Harmonizers. Flanigan was a cousin of the Barbours and joined The Harmonizers beginning on September 20, 1948, becoming their lead vocalist. He also played trombone and double bass.