O'Neal was seen mostly as a guest star on television throughout four decades, beginning in the 1950s. In the early 1960s, he received critical praise for his leading role on Broadway in Tennessee Williams' The Night of the Iguana, but the starring role for the 1964 film version went to Richard Burton. In 1969, he had a leading role in John Huston's The Kremlin Letter and a supporting role in the western El Condor. He appeared in the 1973 hit The Way We Were. In 1972, he portrayed a murderous architect in the Columbo episode "Blueprint for Murder" and in 1978, on the same show, he played a television network executive in the episode "Make Me a Perfect Murder". In 1990, he played the corrupt Police Commissioner Kevin Quinn in Sidney Lumet's Q&A.
With his wife and his brother Michael, O'Neal co-owned a number of successful restaurants beginning in 1963, including "The Ginger Man" on West 64th St. (later renamed O'Neal's); "O'Neal's" on West 57th St., briefly the flagship of an O'Neal's chain; "The Landmark Tavern" on 11th Avenue; and “O’Neal’s Saloon” at West 63rd St. and Columbus Ave., soon retitled "O'Neal's Baloon" (because the word “Saloon” had been outlawed during Prohibition but the neon sign for Saloon had already been created). All were located on the West Side of Manhattan.[4]
Personal life
O'Neal married actress Cynthia Baxter in 1956. They had two sons, Maximilian and Fitzjohn, and remained married until O'Neal's death.[4]