In 1979, Patterson debuted in the then World Wide Wrestling Federation, working as a heel, under the tutelage of manager The Grand Wizard. As a villain, Patterson's primary feuds were with WWF North American Champion Ted DiBiase and WWF World Champion Bob Backlund. During a television taping on June 19 in Allentown, Pennsylvania, Patterson defeated DiBiase for the WWF North American Championship by using a pair of brass knuckles to knock out DiBiase. Patterson was unsuccessful, however, in winning the WWF World Championship from Backlund.
In September 1979, Patterson allegedly won a tournament held in Rio de Janeiro, unifying the WWF North American Championship with the South American Championship to create the WWF Intercontinental Championship in the process. It is, however, widely believed that the aforementioned tournament never actually took place and was invented to add legitimacy to the Intercontinental Championship. It was during Patterson's reign as champion that he turned face, after a botched attempt by the Grand Wizard to "sell" Patterson's contract to "Captain" Lou Albano for $100,000; Albano's protégés, the Wild Samoans, attacked Patterson after he cut a promo insulting Albano.
Patterson held the Intercontinental Championship until April 21, 1980 when he was defeated by Ken Patera in New York City, New York. The match ended in controversial fashion after Patterson placed his right leg on the ropes just before the three count was made.
On May 4, 1981, Patterson's feud with Sgt. Slaughter culminated in an "Alley Fight" in Madison Square Garden.
Patterson retired from wrestling in 1984, and became a color commentator, as well as hosting an interview segment known as "Le brunch de Pat," where he would politely ask questions in English but furtively mock his guests in French. He began working backstage as a road agent and right-hand man to WWF promoter Vince McMahon, and is credited with inventing and booking the Royal Rumble match. In the late 1990s, he also worked in the talent-relations department.
In 1997, Patterson became an onscreen stooge of Vince McMahon. He and Gerald Brisco became comedy heels, aiding McMahon in his rivalries with Stone Cold Steve Austin, Mankind and The Rock. Patterson and Brisco were members of both The Corporation and The McMahon-Helmsley Faction, and used "Real American" as their entrance music to mock Hulk Hogan. They would also parody Hogan's flexing routine as they approached the ring. On June 12, 2000 the McMahon-Helmsley Faction briefly gained control over Kane after they unmasked him, enabling Patterson to photograph his "hideously scarred" face, and threatened to "expose him to the world" if he did not comply. Kane was forced to wrestle The Rock (then his ally) in a No Holds Barred match. However, the film did not develop properly, and Kane turned on the Faction. Patterson became the oldest WWF Hardcore Champion ever on June 19, 2000 after blinding reigning champion Gerald Brisco with champagne and then breaking a second bottle over Brisco's head. On June 25 at King of the Ring, Patterson defended the Championship against Brisco in an hardcore evening gown match booked by Vince McMahon after Patterson and Brisco brawled in the women's locker room. In the course of the match, Crash Holly attacked both men and pinned Patterson to become Hardcore Champion.
The Intercontinental Championship, unified with the World Heavyweight Championship on October 20, 2002, was resurrected on May 18, 2003 at Judgment Day in a Battle Royal. Patterson, as the first ever Intercontinental Champion, was at ringside to present the belt to the victor. Booker T eliminated Christian for the win, but the referee was unconscious. As Patterson attempted to give the belt to Booker T, Christian attacked him, stole the belt and used it to knock out Booker T. The referee then recovered and awarded the match to Christian.
In October 2004, Patterson retired from World Wrestling Entertainment. One of his last acts was a report for WWE which claimed that too much time was being devoted to Triple H, the son-in-law of Vince McMahon. Patterson returned to WWE in a limited capacity in May 2005. While he is now retired as a producer for WWE, he still acts as a consultant. At WWE Breaking Point, Patterson made an appearance in his hometown of Montreal in an in-ring segment with Dolph Ziggler.
On April 10, 2012, Patterson made an appearance on WWE Smackdown: Blast from the Past.