Joseph Nieuwendyk (/ˈnjuːəndaɪk/ NEW-ən-dyke; born September 10, 1966) is a retired Canadian NHL player. Drafted by the Calgary Flames in 1985, he played 20 seasons with the Flames, Dallas Stars, New Jersey Devils, Toronto Maple Leafs, and Florida Panthers. He is one of only 11 players in NHL history to win the Stanley Cup with three different teams, achieving this with Calgary in 1989, Dallas in 1999, and New Jersey in 2003. Nieuwendyk also won a gold medal with Team Canada at the 2002 Winter Olympics. Inducted into the Hockey Hall of Fame in 2011, his number 25 was honored by the Flames in 2014, and he was inducted into the Ontario Sports Hall of Fame the same year. In 2017, he was named one of the '100 Greatest NHL Players' in history.

An accomplished box lacrosse player, Nieuwendyk led the Whitby Warriors to the 1984 Minto Cup national junior championship before focusing on hockey. He played university hockey with the Cornell Big Red, earning All-American honors twice. He won the Calder Memorial Trophy as NHL rookie of the year in 1988, scoring 50 goals as a first-year player. He was a four-time All-Star, won the King Clancy Memorial Trophy in 1995 for leadership and humanitarian work, and was named the Conn Smythe Trophy winner in 1999 as the most valuable player of the postseason. In his career, he played 1,257 games, scoring 564 goals and 1,126 points.

Chronic back pain forced Nieuwendyk's retirement in 2006. He then started a management career, working as a consultant for the Panthers, an assistant general manager for the Maple Leafs, and the general manager of the Dallas Stars from 2009 to 2013. He later worked as a pro scout and advisor for the Carolina Hurricanes until April 2018.

Born in Oshawa, Ontario, Nieuwendyk grew up in Whitby as the youngest of four children to Gordon and Joanne Nieuwendyk, who emigrated from the Netherlands in 1958. His family was sports-oriented; his brother Gil played box lacrosse, and his uncle Ed Kea and cousin Jeff Beukeboom also played in the NHL. His best friend growing up was future NHL teammate Gary Roberts.

Nieuwendyk excelled in both hockey and lacrosse, earning a spot with the Whitby Warriors junior A team at 15 and being named MVP of the 1984 Minto Cup. He later played junior B hockey for the Pickering Panthers before attending Cornell University, where he was named ECAC rookie of the year in 1984–85. Drafted by the Calgary Flames in 1985, he focused on hockey, earning ECAC first-team All-Star and NCAA All-American honors. He left Cornell after his junior year to turn professional, finishing his university career with 73 goals and 151 points in 81 games. Cornell retired his number 25 jersey in 2010.

Nieuwendyk debuted in the NHL with the Flames in 1987, scoring five goals in nine regular season games. In his first full season, he scored 32 goals in his first 42 games, finishing with 51 goals and winning the Calder Memorial Trophy. He repeated the 51-goal feat in 1988–89, leading the league with 11 game-winning goals and helping the Flames win their first Stanley Cup. He continued to excel, becoming the third-fastest player to reach 100 career goals and scoring a career-high five goals in one game in 1989.

Nieuwendyk's tenure with the Flames ended in 1995 when he was traded to the Dallas Stars after a contract dispute. He quickly signed a new deal with the Stars, contributing significantly despite injuries. In 1999, he led the Stars to their first Stanley Cup, winning the Conn Smythe Trophy as playoff MVP. He continued to play at a high level despite injuries, helping the Stars reach the 2000 Stanley Cup Finals.

In 2002, Nieuwendyk was traded to the New Jersey Devils, scoring his 500th career goal and 1,000th point in the 2002–03 season. Despite an injury that kept him out of the Stanley Cup Finals, the Devils won the championship, making Nieuwendyk one of the few players to win the Cup with three different teams. He later joined the Toronto Maple Leafs, scoring 22 goals despite injuries, and finishing his career with the Florida Panthers before retiring due to chronic back pain in 2006.

Internationally, Nieuwendyk represented Canada at the World Junior Championships, World Championships, and the Olympics. He won a silver medal at the 1986 World Junior Championships and a gold medal at the 2002 Winter Olympics.

Known for his two-way play, leadership, and faceoff skills, Nieuwendyk was a key player on every team he joined. He captained the Flames for four seasons and was praised for his leadership and unselfishness, contributing significantly to team successes on and off the ice. His contributions were recognized with induction into the Hockey Hall of Fame and the Calgary Flames' "Forever a Flame" program.

After retiring as a player, Nieuwendyk continued his involvement in hockey through various management roles, including consultant, assistant general manager, and general manager positions. He also served as a pro scout and advisor, contributing to the success of multiple NHL teams.

Nieuwendyk and his wife Tina have three children. His son, Jackson, plays hockey in the British Columbia Hockey League and is committed to play NCAA hockey. Nieuwendyk has also been recognized for his humanitarian efforts, winning the King Clancy Memorial Trophy and supporting various charitable causes throughout his career.