Mayo Methot was married three times and had no children. At the age of 19, she married Cosmopolitan Productions cameraman Jack Lamond. They divorced in 1927. In 1931, Methot married Percy T. Morgan, the co-owner of the Cock n’ Bull restaurant on Hollywood’s Sunset Boulevard. Methot divorced Morgan in February 1937, claiming that Morgan would not allow her to accept an acting role in New York City. Mayo Methot’s third marriage was to actor Humphrey Bogart, whom she had met in the late 1920s and reconnected with in early 1936. They were married on August 28, 1938 in Beverly Hills. Bogart had been married to actresses Helen Menken and Mary Philips before marrying Methot, and blamed his previous divorces on his wives’ careers and their long separations. Two years after Methot and Bogart were married, Methot gave up acting. The two became a high-profile Hollywood couple, but it was not a smooth marriage. Both drank heavily, and Methot gained a reputation for her violent excesses when under the influence. They became known in the press as “The Battling Bogarts,” with Methot widely known, due to her combativeness, as “Sluggy.” Bogart later named his motor yacht Sluggy in her honor. During World War II, the Bogarts traveled Europe entertaining the troops. At one point in their travels during the war, the Bogarts met up with director John Huston in Italy. During a night of heavy drinking, Methot insisted that everyone listen to her perform a song. Though they told her no, she sang anyway. The performance was so bad and embarrassing that Huston and Bogart remembered it years later and based a scene in Key Largo on the incident. It is the scene in which the alcoholic girlfriend (played by Claire Trevor) of the mobster (played by Edward G. Robinson) sings a number off key and while intoxicated. The performance won Trevor an Academy Award.

Numerous battles took place at the Hollywood residence of the famous couple – nicknamed Sluggy Hollow – including one in which Methot stabbed Bogart in the shoulder. The incident was kept out of the press by the publicity department of Warner Bros.. Actress Gloria Stuart recalled in her later years a dinner party at which Methot produced a pistol and threatened to shoot Bogart. The couple separated and reconciled several times over the course of their marriage. While filming To Have and Have Not in 1943, Bogart fell in love with his 19-year old co-star Lauren Bacall and the two began an affair. Methot caught wind of the affair and visited the set often. Bogart attempted to save the marriage but Methot’s alcoholism intensified as did their fighting. Bogart announced that he had moved out of the couple’s home on October 19, 1944. On October 30, Bogart announced that he had reconciled with Methot and that he was “going home. […] In other words, we’ll return to our normal battles.” The reconciliation proved to be short lived; Methot announced that Bogart had moved out of their home yet again on December 3, 1944. Methot filed for divorce on May 10, 1945 in Las Vegas. The divorce was granted one hour after she filed the decree. Bogart married Lauren Bacall on May 21, 1945. After her divorce from Bogart, Methot was unable to renew the career she had given up and became locked into a pattern of alcoholism and depression. In the late 1940s, she moved back to Oregon where her mother helped take care of her. On June 9, 1951, Mayo Methot died at Holladay Park Hospital in Portland. Her death was attributed to acute alcoholism. Methot’s remains are interred at the Portland Memorial Mausoleum in Portland, Oregon.