In 1972 he joined the cast of fledgling soap opera Number 96 playing the role of Janie Somers' new beau Jack Sellars. Back-slapping rough diamond Jack was intended as a guest character to appear for a run of just three weeks, but the makers of the show were impressed with his performance and the character was made into an on-going lead regular in the serial.
Oliver became one of the Number 96's most popular cast members. During his run in the show he married fellow Number 96 actor Lynn Rainbow, and opened a wine bar in Kensington, Sydney cunningly named Jack's Cellar. In late 1973, along with much of the show's regular cast including Lynn Rainbow, he reprised his television role in a feature film spinoff of the serial. Oliver stayed in the role in the series for more than two years, finally electing to leave the series in mid 1974. After leaving the serial he quickly returned to television guest starring roles and roles of varying size in feature films. He briefly returned to Number 96 in the role of Jack Sellars in September 1975.
Oliver's film roles included ABBA: The Movie. His primary role in the film is as ABBA's gruff bodyguard; however, he additionally appears in the film as a barman and as a chatty moustached taxi driver shown mainly from behind. Through the late 1970s and the 1980s, Oliver appeared in guest and regular roles in many Australian drama series and serials, including Prisoner, Holiday Island and Sons and Daughters.
He had a notable role in 1979 alongside character actor David Brogan in the critically panned series The Man in the Brown Suede Jacket. He also appeared in the acclaimed miniseries The Dismissal. With actor Steven Grives he started a film production company which produced the film The Right Hand Man in 1987. Oliver has been nominated for the Australian Film and Television Awards for Best Supporting Actor three times. Oliver also acted on the stage, appearing in such plays as The Knack, Cactus Flower, How the Other Half Loves and The Club.
Today Oliver is most known for his long-running role of Lou Carpenter in Neighbours. He first appeared for a handful of episodes as lovable rogue used-car salesman Lou, Madge Ramsay's former flame, in 1988. In early 1992 the character was reintroduced to the series and has been a key character ever since. He is now the show's longest serving continuous character ever, now in his seventeenth year.
Tom Oliver's name appears near the bottom of the IMDB cast list of the 1962 Cliff Richard musical Summer Holiday, although which character he played is uncertain and his name does not appear on the film credits.