Hartman became well-known in the late 1980s when he joined the sketch comedy show Saturday Night Live. He won fame for his impressions, particularly of President Bill Clinton, and stayed on the show for eight seasons. Called "the Glue" for his ability to hold the show together and help other cast members, Hartman won a Primetime Emmy Award for his SNL work in 1989. In 1995, after scrapping plans for his own variety show, he starred as Bill McNeal in the NBC sitcom NewsRadio. He also had frequent roles on The Simpsons, and appeared in the films Houseguest, Sgt. Bilko, Jingle All the Way, and Small Soldiers.
Hartman had twice divorced before he married Brynn (née Omdahl) in 1987; the couple had two children together. However, their marriage was fractured, due in part to Brynn's drug use. On May 28, 1998, Brynn shot and killed her husband while he slept in their Encino, Los Angeles home, then committed suicide several hours later. In the weeks following his death, Hartman was celebrated in a wave of tributes. Dan Snierson of Entertainment Weekly opined that Hartman was "the last person you'd expect to read about in lurid headlines in your morning paper."
Hartman married Gretchen Lewis in 1970 and they divorced sometime before 1982. He married real estate agent Lisa Strain in 1982 and their marriage lasted three years. Strain told People that Hartman was reclusive off screen and "would disappear emotionally ... he'd be in his own world. That passivity made you crazy." Hartman married former model and aspiring actress Brynn Omdahl (born Vicki Jo Omdahl) in November 1987, having met her on a blind date the previous year. Together they had two children, Sean and Birgen Hartman. The marriage had difficulties—Brynn reportedly felt intimidated by her husband's success and was frustrated that she could not find any on her own, although neither party wanted a divorce. Hartman considered retiring to save the marriage. He tried to get Brynn acting roles but she became progressively more reliant on narcotics and alcohol, entering rehab several times. Because of his close friendship with SNL associate Jan Hooks, Brynn joked on occasion that Hooks and Hartman were married "on some other level."
On the evening of May 27, 1998, Brynn Hartman visited the Italian restaurant Buca di Beppo in Los Angeles County, California, with producer and writer Christine Zander, who said she was "in a good frame of mind." After returning to the couple's Encino home, Brynn started a "heated" argument with Hartman, who threatened to leave her if she started using drugs again, and went to bed. While he slept, Brynn entered his bedroom shortly before 3 a.m. with a .38 caliber handgun and fatally shot him twice in the head and once in his side. She was intoxicated, and had recently taken cocaine.
Brynn drove to the home of her friend Ron Douglas and confessed to the murder but initially he did not believe her. The pair drove back to the house in separate cars after which Brynn called another friend and confessed a second time. Upon seeing Hartman's body, Douglas called 911 at 6:20 a.m. Police subsequently arrived and escorted Douglas and the Hartmans' two children from the premises. Brynn had locked herself in the bedroom, and committed suicide by shooting herself once in the head.
Los Angeles police stated Hartman's death was due to "domestic discord" between the couple. A friend recalled that Brynn allegedly "had trouble controlling her anger ... She got attention by losing her temper." A neighbor of the Hartmans told a CNN reporter that the couple had been experiencing marital problems: "It's been building, but I didn't think it would lead to this." Steve Guttenberg commented that the pair were "a very happy couple, and they always had the appearance of being well-balanced."
Other causes for the incident were later suggested. Before committing the act, Brynn was taking the antidepressant drug Zoloft. A wrongful-death lawsuit was filed in 1999 by Brynn's brother, Gregory Omdahl against the drug's manufacturer, Pfizer, and her child's psychiatrist Arthur Sorosky, who provided samples of Zoloft to Brynn. Hartman's friend and ex-SNL colleague Jon Lovitz has said that his former NewsRadio co-star Andy Dick gave cocaine to Brynn, causing her to relapse and suffer a mental breakdown. Dick claims to have known nothing of her condition. In 2006, Lovitz claimed that Dick had approached him at a restaurant and said, "I put the Phil Hartman hex on you; you're the next one to die." The following year at the Laugh Factory comedy club in Los Angeles, he and Dick had a further altercation over the issue. Dick does not believe he is at fault in relation to Hartman's death.
Brynn's sister Katharine Omdahl and brother-in-law Mike Wright are raising the two Hartman children in Edina, Minnesota. Hartman's will stipulated that each child will receive their inheritance over several years after they turn 25. The total value of Hartman's estate was estimated at $1.23 million. As per Hartman's will, his body was cremated by Forest Lawn Memorial Park and Mortuary in Glendale, California, and his ashes were scattered over Santa Catalina Island's Emerald Bay.