Braxton Bragg "Opp" O'Mara (September 15, 1896 – May 24, 1969) was an American football player and coach of football and basketball. He served as a football player-coach for one season at the University of Southern Mississippi–then known as Mississippi Normal College–in 1920, compiling a record of 4–2–1. His stint as a player at Hattiesburg was sandwiched between two stints as a player at the University of Mississippi (1918–1919, 1921). O'Mara graduated from the University of Mississippi School of Medicine in 1922.