Michael Dean Bossy (January 22, 1957 – April 15, 2022) was a Canadian professional ice hockey player with the New York Islanders of the National Hockey League. He spent his entire NHL career, which lasted from 1977 to 1987, with the Islanders, and was a crucial part of their four consecutive Stanley Cup championships in the early 1980s.

Bossy won the Calder Memorial Trophy in 1978 as NHL rookie of the year when he set the then-record for most goals by a rookie with 53. He won the Conn Smythe Trophy in the 1982 Stanley Cup playoffs as the most valuable player and the Lady Byng Trophy for combining high quality play with sportsmanship three times. He led the NHL in goals twice and was second three other times. Bossy was voted to the league's first all-star team as right wing five times, with three further selections to the second all-star team. He is one of two players (Jack Darragh being the other) to score consecutive Stanley Cup-winning goals (1982 and 1983) and the only player to record four game-winning goals in one playoff series (1983 Conference Final).

Bossy is the NHL's all-time leader in average goals scored per regular season game, holds the NHL's fourth-highest all-time average points scored per regular season game, and is the second of five players to score 50 goals in 50 games, being the first to accomplish this feat 36 years after Maurice Richard did so. He jointly holds the record for most 50-goal seasons with Wayne Gretzky and Alexander Ovechkin with nine, being the only player of the three whose 50-goal seasons ran consecutively.

Bossy was elected to the Hockey Hall of Fame in 1991, was named one of the 100 Greatest NHL Players in history, and is considered one of the greatest goal scorers in NHL history.

Bossy was the fifth son among ten children, and grew up in a family of Detroit Red Wings fans in the parish of Saint-Alphonse, in the Ahuntsic-Cartierville area of Montreal. Bossy attended St. Pius X Comprehensive High School and then Laval Catholic High School. His mother Dorothy was English and French-Canadian, and his father Borden, who maintained a backyard ice rink at their apartment building, was Ukrainian. When he was 12 years old, Bossy broke a kneecap while competing in long jump at school, later developing chronic knee problems during his hockey career.

As a youth, Bossy played in the 1969 Quebec International Pee-Wee Hockey Tournament with a minor ice hockey team from Montreal. He started his junior career with the Laval National of the Quebec Major Junior Hockey League at the age of 15. Despite scoring 309 goals in five seasons, he was considered "not rugged enough" and defensively weak by NHL scouts. His total of 532 points remains a QMJHL record, and his 309 goals is the record for all of major junior. Bossy's #17 is retired by the Acadie–Bathurst Titan, the current incarnation of the former Laval franchise.

Bossy, who had averaged 77 goals per season in junior with Laval, was passed over by twelve teams in the 1977 NHL amateur draft, including the New York Rangers and Toronto Maple Leafs, who each passed over him twice. Toronto expected him to hold out for more than they wanted to pay, according to Bossy, while the Rangers opted for highly-ranked Lucien DeBlois and Ron Duguay. Other teams passed for various reasons: the Buffalo Sabres took Ric Seiling, preferring his checking ability, while the Cleveland Barons, who had the fifth overall pick, passed when Bossy's agent Pierre Lacroix gave the Barons inflated salary requirements, prompting them to select Mike Crombeen instead. Scotty Bowman, coach of the Montreal Canadiens, later regretted that Montreal had passed on Bossy; Bowman and his assistant Claude Ruel had each been impressed with Bossy's play – and scoring – in person, but team scouts questioned his toughness and the Canadiens took Mark Napier with their first pick instead.

The New York Islanders picked Bossy with the 15th overall selection. General manager Bill Torrey was torn at first between taking Bossy and Dwight Foster. Bossy was known as a scorer who could not check, while Foster, who had led the Ontario Hockey Association with 143 points, had a defensive aspect to his game. Various stories exist explaining who persuaded Torrey to select Bossy. One common story credits coach Al Arbour, who figured it would be easier to teach a scorer how to check. Another credits Islanders scout Harry Saraceno, while another credits both Arbour and Saraceno.