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 further 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 third-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 tied for the record for most 50-goal seasons with Wayne Gretzky and Alexander Ovechkin with nine, though his were consecutive as opposed to Gretzky's and Ovechkin's being non-consecutive; he thus is the sole record-holder for most consecutive 50-goal seasons.

Bossy was elected to the Hockey Hall of Fame in 1991. In 2017, he was named one of the 100 Greatest NHL Players in history.