William Robert Guerin (born November 9, 1970) is an American former professional ice hockey player and the current general manager of the Minnesota Wild.

Guerin played 18 seasons in the National Hockey League (NHL), winning two Stanley Cup championships with the New Jersey Devils and Pittsburgh Penguins.

Internationally, Guerin represented the United States in the Olympics in 1998, 2002 and 2006, and participated in two Ice Hockey World Championships.

Midway through the 1997–98 season, Guerin was traded (along with Valeri Zelepukin) to the Edmonton Oilers in exchange for Jason Arnott and Bryan Muir.

[5] Playing on a line with former Oiler teammate Doug Weight, Guerin revived his career, easily eclipsing his disappointing goal-scoring mark from the 2005–06 season.

[10] Guerin won the Stanley Cup on June 12, 2009, with the Penguins, defeating the Detroit Red Wings by a final score of 2–1 for Game 7 at Joe Louis Arena.

His 14 years between Stanley Cups as a player was the third-longest wait in NHL history, behind Chris Chelios (16) and Mark Recchi (15).

Guerin denied any wrongdoing on his part, claiming that he had "promptly brought (the allegation) to Pittsburgh Penguins senior management".

[22] The United States Center for SafeSport opened an investigation on Guerin over his alleged role in the whistleblower lawsuit.

[22] In December 2023, the Wild conducted an investigation after an employee filed a verbal abuse complaint against Guerin to human resources.