A gifted speaker from a very young age, Gortner received his ordination as a preacher when he was only four years old and spent his childhood and early teenage years traveling throughout the United States as a celebrity Christian Revivalist movement member. He was later the subject of an Academy Award-winning documentary film titled Marjoe.
When Gortner was a very young child, he was taught evangelical preaching techniques by his parents and was instructed to tell the public that he had experienced a heavenly vision while nearly drowning during a bath.
He appeared in several B-movies, including The Food of the Gods and The Gun and the Pulpit.
After his minister father, Vernon Gortner, stole the millions of dollars that young Marjoe had made on the revivalist circuit, Marjoe Gortner parted with the rest of his family and pursued a career as an actor. In the late 1970s, he was briefly married to screen actress Candy Clark.
He co-starred with Charlton Heston and Ava Gardner in Earthquake, an Oscar-winning disaster movie that premiered in 1974.