Sullivan began coaching professional hockey during the 2002–03 season, when he became the head coach of the
Providence Bruins of the
American Hockey League (AHL). In his only season, his team had a 41–17–9–4 record. Sullivan was hired as the 26th head coach of the
Boston Bruins in 2003 by then-general manager
Mike O'Connell. His first season with the Bruins was highly successful, as he led them to a 41–19–15–7 record, 104 points and a first-place finish in the
Northeast Division. However, they were eliminated in the conference quarterfinals of the
2004 Stanley Cup playoffs by the
Montreal Canadiens. After the
2004–05 NHL lockout, Sullivan and the Bruins struggled to win in the new NHL, as they ended the
2005–06 season with a dismal 29–37–16 record, missing the playoffs and finishing last in the Northeast Division. He was subsequently fired by the incoming general manager
Peter Chiarelli on June 27, 2006, and was replaced by
Dave Lewis. Sullivan served as an assistant coach of the U.S. Olympic hockey team at the
2006 Winter Olympics. On May 31, 2007, he was named assistant coach of the
Tampa Bay Lightning. He was then promoted to associate coach the following season. On July 16, 2009, he was named assistant coach of the
New York Rangers. On July 3, 2013, he was named assistant coach of the
Vancouver Canucks. On January 20, 2014, Sullivan was named interim head coach of the Canucks, while head coach
John Tortorella served a six-game suspension. On January 21, in his first game as acting head coach, the Canucks would go on to record a 2–1 victory over the
Edmonton Oilers. On May 1, Sullivan, along with head coach Tortorella, were relieved of their respective duties in the Canucks organization. Sullivan subsequently joined the
Chicago Blackhawks as a player development coach. On June 18, 2015, the
Pittsburgh Penguins named Sullivan as the new head coach of their
American Hockey League affiliate, the
Wilkes-Barre/Scranton Penguins. He was named head coach of the Pittsburgh Penguins on December 12, 2015, upon the firing of
Mike Johnston. On June 12, 2016, Sullivan became just the sixth head coach in NHL history to win the
Stanley Cup after being hired mid-season. He did so when the Penguins defeated the
San Jose Sharks in the
2016 Stanley Cup Final. Sullivan joined both
Scotty Bowman (
1992) and
Dan Bylsma (
2009) as the third coach in franchise history (and the sixth in NHL history) to win the Stanley Cup following a mid-season coaching change. Sullivan is also the first coach to lead the Penguins to consecutive Stanley Cup championships with their victory over the
Nashville Predators in the
2017 Stanley Cup Final, and is the only American-born head coach to win the Stanley Cup multiple times. On December 16, 2017, he recorded his 100th career win with the Penguins becoming just the fourth coach to do so for the organization. On July 5, 2019, Sullivan signed a four-year contract extension. After a 5–2 win against the
Chicago Blackhawks on October 16, 2021, Sullivan became the winningest coach in the Penguins history, surpassing Dan Bylsma's record with 253 wins behind the Penguins bench. On April 12, 2023, with the
New York Islanders victory over the Montreal Canadiens, the Penguins missed the playoffs for the first time since the
2005–06 season. After 10 seasons as head coach, Sullivan was relieved of his coaching duties with the Penguins on April 28, 2025. His dismissal came following the
2024–25 season, where the team failed to qualify for the playoffs for the third straight season. On May 2, 2025, Sullivan was named the head coach of the
New York Rangers. Sullivan served as the head coach of the U.S. Olympic hockey team at the
2026 Winter Olympics. Sullivan recruited his mentor
John Tortorella to serve as an assistant coach. The United States won the gold medal, defeating
Canada 2–1 in overtime. ==Career statistics==