Hugh Marjoe Ross Gortner was born in 1944 in Long Beach, California, into a family with a long evangelical heritage. The name "Marjoe" is a portmanteau of the biblical names "Mary" and "Joseph". His father Vernon was a third-generation Christian evangelical minister who preached at revivals. His mother, who has been labelled as "exuberant," was the person who introduced him as a preacher, and is notable for his success as a child. Vernon noticed his son's talent for mimicry and his fearlessness of strangers and public settings. His parents claimed that the boy had received a vision from God during a bath, and he started preaching. Marjoe later said this was a fictional story that his parents forced him to repeat. He claimed they compelled him to do this by using mock-drowning episodes; they did not beat him as they did not want to leave bruises that might be noticed during his many public appearances.

They trained him to deliver sermons, complete with dramatic gestures and emphatic lunges. When he was four, his parents arranged for him to perform a marriage ceremony attended by the press, including Photographers from Life and Paramount studios. Until his teenage years, Gortner and his parents traveled throughout the United States holding revival meetings, and by 1951 his younger brother Vernoe had been incorporated into the act. As well as teaching Marjoe scriptural passages, his parents also taught him several money-raising tactics, including the sale of supposedly "holy" articles at revivals. He would promise that such items could be used to heal the sick and dying.

In the late 1960s, Gortner experienced a crisis of conscience about his double life. He decided his performing talents might be put to use as an actor or singer. When approached by documentarians Howard Smith and Sarah Kernochan, he agreed to let their film crew follow him throughout 1971 on a final tour of revival meetings in California, Texas, and Michigan.

He became a Celebrity again during the 1970s when he starred in Marjoe (1972), a behind-the-scenes documentary about the lucrative Business of Pentecostal preaching. This won the 1972 Academy Award for Best Documentary Film. This documentary now is noted as one of the most vehement criticisms of Pentecostal preaching.

He began his acting career with a featured role in The Marcus-Nelson Murders, the 1973 pilot for the Kojak TV series. In 1974 he made several appearances in film and television. In the disaster film Earthquake he was Sgt. Jody Joad, a psychotic grocery manager-turned-National Guardsman, the main antagonist. He starred in the television movies The Gun and the Pulpit and Pray for the Wildcats, and appeared in an episode of Nakia, a 1974 police drama on ABC.

From 1978 to December 14, 1979, Gortner was married to Actress Candy Clark. Until 2009, Gortner produced Celebrity Sports Invitational charity golf tournaments and ski events to raise money for charities such as the Dream Foundation and Robert F. Kennedy, Jr.'s Waterkeeper Alliance, retiring in January 2010.

In the early 1980s Gortner hosted the short-lived reality TV series, Speak Up, America. He appeared frequently in the 1980s Circus of the Stars specials. He also played a terrorist preacher in a second-season episode of Airwolf, and appeared on Falcon Crest as corrupt psychic-cum-medium "Vince Karlotti" (1986–87). His last role was as a preacher in the western Wild Bill (1995).

In 2008, the Melbourne Underground Film Festival in Melbourne, Australia held the first retrospective of the cinematic works of Marjoe Gortner as part of their ninth festival.

In 2007, the Philadelphia Live Arts Festival commissioned actor and Writer Brian Osborne to write a one-man play about Gortner. The play, The Word, premiered at the Festival with Suli Holum as Director and main collaborator. In 2010, the play was recreated as The Word: A House Party for Jesus, with Director Whit MacLaughlin. The new play opened October 14, 2010, in Philadelphia, Pennsylvania and has since been performed in New York (the Soho Playhouse), Los Angeles, Philadelphia (the 2011 NET Festival), and Pittsburgh, Pennsylvania (the Kelly Strayhorn Theater), with other productions planned for Austin, Chicago, and Minneapolis.

Unbeknownst to everyone involved – including, at one point, his father – he gave "backstage" interviews to the filmmakers between sermons and revivals, some including other Preachers, explaining intimate details of how he and other ministers operated. The filmmakers also shot him while counting the money he had collected during the day, later in his hotel room. The resulting film, Marjoe, won the 1972 Academy Award for best documentary.