It was during the 1960s and 1970s, however, that O'Loughlin would become virtually ubiquitous on TV, his workload decreasing only slightly during the century's final two decades. One of his early guest-starring roles was on "A Man for Mary" episode of
ABC's 1962 comedy-drama
Going My Way. He appeared in "Twenty Miles from Dodge", a 1965 episode of
Gunsmoke. O'Loughlin played a tough but not insensitive gang leader of stagecoach robbers holding the passengers as hostages for ransom. Among them was Miss Kitty (
Amanda Blake), who comforts the freezing and hungry while battling the desperadoes, and a feisty, crafty fellow passenger played by
Darren McGavin. Years later, O'Loughlin reunited with
Gunsmoke lead actor James Arness in the
made-for-TV film ''
McClain's Law'', structured as the pilot for
Arness' 1981–82 police detective series. He also appeared on
Quincy as Adam Beale, chief of a hijack containment unit, working to take down terrorists hijacking a plane with a fatal virus on board. ''. Clockwise from the top:
Georg Stanford Brown (Terry Webster),
Kate Jackson (Jill Danko), Gerald S. O'Loughlin (Eddie Ryker),
Bruce Fairbairn (Chris Owens) and
Sam Melville (Mike Danko) in 1975 O'Loughlin appeared in an episode of the 1961 television series
The Asphalt Jungle. In 1966 he portrayed truck driver Carl Munger (S2:Ep7) and in 1972 he portrayed a robber named Kulhane (S7:Ep21) in the TV series
The F.B.I. He appeared in three episodes of
Hawaii Five-O. The first was aired January 29, 1969 in the episode "The Box". O'Loughlin played the central figure of a group of prison inmates who take Hawaii Five-O chief Steve McGarrett (
Jack Lord) hostage. The second was called "Six Kilos" and was broadcast on March 12, 1969 (playing the same character as in "The Box"), and the third (September 16, 1970) was called "A Time to Die". He also appeared on
Cannon on February 22, 1972, in the episode "Flight of the Hawks", and on episode 16 of the TV show
The Green Hornet. In Season 2 Episode 22 of
Mission: Impossible, he played a killer for hire. In 1970–1971, O'Loughlin portrayed Devin McNeil in the
CBS crime drama
Storefront Lawyers (which was later revised and retitled and became
Men at Law). From 1972 to 1976 O'Loughlin appeared as Lt. Ed Ryker on
The Rookies. In 1978, he appeared in the pilot episode of
The Eddie Capra Mysteries, and had roles in TV miniseries such as
Wheels (1978),
Women in White (1979),
Roots: The Next Generations (1979) and
Blind Ambition (1979). He also appeared as Sgt. O'Toole in the 1983 made-for-TV miniseries
The Blue and the Gray. Also in 1983, he appeared as Gen. Schwerin, hoping to meet
Marilyn Monroe, in the
M*A*S*H episode "
Bombshells". He was also a regular on the series
Automan (1983) and
Our House (1986). Also in 1986, O'Loughlin played the part of Mr. Parks in a first season episode of
Highway to Heaven entitled "The Brightest Star". In 1988, he played Tom Callahan in
Dirty Dancing. In 1992 he appeared as Ben Oliver in
Murder She Wrote in the episode "Badge of Honor". ==Stage==