Liam Sullivan was an American actor, singer, and comedian, originally from Jacksonville in west central Illinois. He began acting while a student at Illinois College and continued in theater at Harvard University. In 1951 he began his career on Broadway appearing in "The Constant Nymph".
Over his acting career, Sullivan played many roles in multiple television series. In the mid-1950s, he appeared on the religion anthology series, Crossroads. Sullivan and Angie Dickinson appeared together in the episode "Point of Honor" of the syndicated American Civil War drama series, Gray Ghost. He guest starred as Jason Douglas in the 1960 episode "The Target" of the syndicated western series Tombstone Territory, with fellow guest star Warren Oates. In 1961 & 1962 Sullivan made three guest appearances on Perry Mason, and in each episode played the murder victim: Lloyd Farrell in "The Case of the Fickle Fortune," Tom Gilrain in "The Case of the Crying Comedian," and title character 'Dickie' Durham in "The Case of the Unsuitable Uncle." He also played "Merodach" in Adam-12 in Season 2, in the episode "Shoplift"