Jon-Erik Hexum (/ˈhɛksəm/; November 5, 1957 – October 18, 1984) was an American actor and model, known for his lead roles in the TV series Voyagers! and Cover Up, and his supporting role as Pat Trammell in the biopic The Bear. He died by a self-inflicted blank cartridge gunshot to the head in a game of Russian roulette while on the set of Cover Up. He was seen as the "next big thing" in Hollywood for his looks, charisma, and ambition. Hexum was a popular sex symbol during his time.

Hexum was born in Englewood, New Jersey, in 1957, to Thorleif Andreas Hexum, a Norwegian immigrant, and Gretha Olivia Paulsen, a Minnesota-born American of Norwegian parentage. He and his elder brother Gunnar were raised in Tenafly by their mother after their parents divorced when Hexum was four. As a single parent after the divorce, Hexum's mother had to work two jobs to support him and his brother. In an interview, Hexum said his mother exposed him to theater arts and music at a young age: "She was wonderful when we were growing up. Somehow she found money to buy us a piano, we got to go to the theater periodically, and I took singing and dancing lessons".

At Tenafly High School, Hexum was an active student, participating in the school's marching band and performing at the 1973 Rose Parade in Pasadena. He also served as drum major of the marching band in his senior year and became the first male cheerleader in his school's history. He also played roles in his school's productions of Carousel and had one of the starring roles in The Pajama Game as a senior. In addition, Hexum was also the senior class president at Tenafly, graduating in 1976.

Hexum went on to Case Western Reserve University in Cleveland to study biomedical engineering and soon transferred to Michigan State University in East Lansing, Michigan. During that time, he worked as a radio disc jockey, played football (mainly as a backup) for the Spartans in 1978, and acted in minor stage roles. Hexum graduated from MSU with a Bachelor of Arts in political philosophy.

Hexum kept himself fit for roles, as he had been playing football and soccer since he was 8. He also wrestled, swam, and lifted weights, and would work out three times a week at the gym.

A few days after graduation, he moved to New York in 1980 to pursue his acting career. While working as an apartment cleaner, he met Bob LeMond of LeMond/Zetter Management, John Travolta's manager. LeMond saw great potential in Hexum. At LeMond's urging, Hexum relocated to Los Angeles in September 1981 to audition for a movie called Summer Lovers; he lost the part to Peter Gallagher. In 1982, Hexum won the lead role in the NBC TV series Voyagers! as Phineas Bogg, a former pirate turned time traveler. Voyagers! aired on Sundays and did not fare well in the ratings against 60 Minutes, the highest rated primetime show at the time. As a result, the series was cancelled.

Hexum was then cast opposite Joan Collins in the 1983 made-for-television movie Making of a Male Model, produced by Aaron Spelling. The TV movie was a ratings hit, ranking in the Top 10 for the week it premiered on ABC. Making of a Male Model featured Hexum's character shirtless in various scenes. This combined with the high ratings made Hexum a sex symbol. Despite this, Hexum expressed some misgivings about doing the movie afterwards calling the movie "trashy." Shortly before his death, Hexum said "it turned out to be a lot more exploitative than I anticipated. I didn't realize how they were going to package the show, how many scenes were going to be shirtless for no apparent reason." Fresh off Making of a Male Model, Hexum was a guest star in another Spelling production, a 1984 episode of ABC's primetime drama Hotel. In his appearance, Hexum played Prince Erik, a Prince Charming–type character who woos a Cinderella-type character played by Emma Samms. Later in 1984, Hexum was cast opposite Jennifer O'Neill in the CBS primetime series Cover Up, playing Mac Harper, an undercover CIA operative posing as a model. He was the subject of a profile in the November 1984 issue of Playgirl and appeared clothed and shirtless but not nude in photographs taken for the magazine. The show continued after his death, his character written out of the plot.

That same year Hexum played the terminally ill quarterback Pat Trammell, a small role in the feature film The Bear, a tribute to the University of Alabama football coach Paul "Bear" Bryant, played by Gary Busey. To prepare for the role, Hexum cut his hair short to match Trammell's appearance and prior to filming visited Alabama and met with Trammell's family and teammates. The Bear would be Hexum's sole feature film performance, released just three weeks before his death. Prior to the accident he had started a relationship with actress E.G. Daily. A self-described "extreme miser", Hexum owned a modest house in Burbank, California, with sparse furnishings, and drove a 1954 Chevy Bel Air. Shortly before his death, Hexum set up a company to produce and direct films.