was born on October 1, 1935 in Chicago, Illinois, USA. He was an actor, known for The Doctors (1963), The Adams Chronicles (1976) and The Heiress (1961). He died on June 14, 1989. 
 

Aside from The Doctors (1963), he was also on The Secret Storm (1954), Our Private World (1965) (a nighttime soap opera) and Search for Tomorrow (1951).

 

One of his later roles was as Dr. Alan Glaser on Another World (1986–87). The role started out as that of a seemingly good doctor, but in the end, the good doctor was revealed to be the "Sin Stalker," responsible for killing off several supporting characters on the show.
 

Other television shows O'Brien starred in include The Adams Chronicles (TV mini series), The United States Steel Hour, The Heiress (TV Movie), The Cosby Show and Spenser: For Hire (as recurring character Tom Flaherty). He also appeared in the movie Arthur 2: On the Rocks.