At age 12 Hull was playing organized hockey on a team with his father. He was put on the Blackhawks' negotiating list, and thereafter he played amateur hockey with financial support for his education by the club. He dropped out of St. Catherines (Ontario) Collegiate School to join the Blackhawks in 1957, at first playing centre but later forward. In the 1959–60 season he led the NHL in scoring with 39 goals, and two seasons later he scored 50 goals, matching a record set by Maurice Richard. In 1965–66 Hull established a new record with 54 goals, 43 assists, and 97 points. His great skating speed and bulletlike shot helped earn him the nickname “Golden Jet.” He won the Art Ross Trophy for highest scorer (1960, 1962, and 1966), the Hart Trophy for most valuable player (1965 and 1966), and the Lady Byng Trophy for ability combined with sportsmanship (1965). In 1961 he helped the Blackhawks win the Stanley Cup.

In 1972 Hull joined the Winnipeg Jets of the World Hockey Association (WHA); his signing led to larger salaries in the NHL as teams sought to keep players from switching leagues. He played with the Winnipeg Jets from 1972 to 1979, and in the 1974–75 season he scored 77 goals. He returned to the NHL in 1980, playing on the Hartford Whalers, but retired after the 1980–81 season. His final totals included 610 NHL goals, 560 assists, and 1,170 points; in the WHA, 303 goals, 335 assists, and 638 points. During his NHL career he registered 50 or more goals in five seasons and four such seasons in the WHA. In 1983 he was inducted into the Hockey Hall of Fame. His son Brett Hull also was an outstanding player in the NHL.