George Peter DeBoer (born June 13, 1968) is a Canadian professional ice hockey coach and former player who is the head coach for the New York Islanders of the National Hockey League (NHL). He was selected in the 12th round, 237th overall, by the Toronto Maple Leafs in the 1988 NHL entry draft but never played in the NHL, instead playing for the Milwaukee Admirals of the International Hockey League (IHL).

A two-time winner of the Ontario Hockey League (OHL) Coach of the Year award, DeBoer was a junior hockey head coach for 13 seasons with the Detroit Whalers (1995–1997), Plymouth Whalers (1997–2001) and Kitchener Rangers (2001–08), the latter of which he led to a Memorial Cup victory in 2003. DeBoer is also a co-owner of the Oshawa Generals. He served as the head coach of the Florida Panthers from 2008 to 2011, the New Jersey Devils from 2011 to 2014, the San Jose Sharks from 2015 to 2019, the Vegas Golden Knights from 2020 to 2022, and the Dallas Stars from 2022 to 2025. DeBoer has the most playoff wins without a Stanley Cup championship with 97.

DeBoer was drafted 237th overall by the Toronto Maple Leafs in the 1988 NHL entry draft. At the time, he was playing with the Windsor Spitfires in the OHL, and in his best offensive season, he scored 45 goals and 46 assists for 91 points. After Windsor, DeBoer went on to play for the Milwaukee Admirals of the International Hockey League (IHL), playing two full seasons with them. In his last season with the Admirals, he scored 27 goals and 34 assists for 61 points and retired after that season.

DeBoer became an assistant coach for the Detroit Junior Red Wings during the 1994–95 season. During the 1995 off-season, the club was renamed the Detroit Whalers and DeBoer was promoted to the dual position of head coach-general manager after Paul Maurice left the team to become the coach of the NHL's Hartford Whalers. DeBoer guided the Whalers to a first-place finish in the West Division, as Detroit advanced to the third round in the playoffs. In 1996–97, Detroit struggled to a 26–34–6 record and was eliminated in the first round of the post-season.

The Whalers renamed themselves the Plymouth Whalers during the 1997 off-season, and the team rebounded to a second-place finish in the West Division with a 37–22–7 record – for the second time in three seasons, they advanced to the third round of the playoffs. In 1998–99, DeBoer led the team to an OHL-leading 106 points, earning them the Hamilton Spectator Trophy, and DeBoer winning the Matt Leyden Trophy as OHL Coach of the Year. Plymouth had a disappointing playoff run, however, as they were defeated by the underdog London Knights in the second round of the playoffs.

In 1999–2000, Plymouth once again had the best record in the league, earning DeBoer his second straight Matt Leyden Trophy. The Whalers advanced all the way to the J. Ross Robertson Cup Finals before losing to the Barrie Colts 4–2 in the seventh and series deciding game.

The Whalers had another very successful season in 2000–01, winning the West Division for the third consecutive season and having the second best record in the League. Plymouth got hot in the playoffs, winning their first nine games, and advanced to the J. Ross Robertson Cup for the second season in a row. In the final round, Plymouth lost to the Ottawa 67's in six games.

After the season, both DeBoer and his assistant, Steve Spott, decided to leave the Whalers and join the Kitchener Rangers in similar positions.