Growing up and playing hockey in his hometown Gatineau, Brière played Bantam hockey in 1992–93 for the Abitibi Regents before graduating to the AAA Gatineau Intrepide of the Quebec Midget League for the 1993–94 season. In his first season with the Intrepide, the team captured the bronze medal at the 1994 Air Canada Cup, where Briere was the top scorer and named Top Forward. Soon after, he was drafted by the Drummondville Voltigeurs in the 1994 QMJHL Draft. Brière's number 14 was retired by this team, on January 21, 2007, during a ceremony in the Marcel Dionne Center of Drummondville.
In his rookie season, he recorded 123 points, third overall in the league, was awarded the Michel Bergeron Trophy as league rookie of the year, and the Marcel Robert Trophy as scholastic player of the year. The following season, he improved to 163 points, earning the Jean Béliveau Trophy as the league's leading scorer. He was also named the QMJHL Humanitarian of the Year and awarded the Ford Cup as offensive player of the year. Despite a remarkable six-game, 18-point post-season effort from Brière, Drummondville was not able to advance from the divisional round-robin.
After Brière was drafted by the Phoenix Coyotes in the first round, 24th overall, in the 1996 NHL Entry Draft, he returned to Drummondville for one more season. He recorded 130 points, finishing in the top three in league scoring for the third consecutive season, and was awarded the Frank J. Selke Memorial Trophy as the most sportsmanlike player.
Graduating from major junior, Brière split his first four seasons in the NHL between the Coyotes and their American Hockey League (AHL) affiliate, the Springfield Falcons. In his first professional season in 1998, he recorded 92 points in 68 games and was awarded the Dudley "Red" Garrett Memorial Award as top rookie, as well as being named the AHL's First Team All-Star center. He remains the third leading scorer in Falcons' franchise history.
Brière's training regimen became newsworthy in 2001 when it became known that, in order to overcome his diminutive size (at 5 ft. 9 in., he is comparatively small by NHL standards), he had begun off-season strength training with Canadian World's Strongest Man competitor Hugo Girard, who shares Gatineau as a hometown. He earned a consistent NHL roster spot in the second half of the 2000–01 season and spent his first full season with the Coyotes in 2001–02, recording 60 points.
At the 2002–03 trade deadline, the Coyotes traded Brière to the Buffalo Sabres alongside a third round pick in the 2004 NHL Entry Draft in exchange for Chris Gratton and a fourth round pick in 2004. After playing with SC Bern of the Swiss Nationaliiga A during the 2004–05 NHL lockout, he returned to Buffalo and emerged as a bona fide NHL star, beginning with a 58-point season in just 48 games during the 2005–06 campaign. Brière was kept out of the lineup for 32 games due to an abdominal injury suffered in January that required surgery and a two-game suspension following an inadvertent high-stick to Boston Bruins defenceman Brian Leetch. Completing the season with the Sabres healthy, Brière helped lead the club to their first post-season berth in four years. During this time he earned the nickname "Cookie Monster" from Sabres play by play announcer Rick Jeanneret for his notoriety for shooting top shelf, "where momma hides the cookies." Playing on a rejuvenated team that included stars Chris Drury, Thomas Vanek and Brian Campbell, the Sabres advanced to the conference-finals, paced by Brière's team-high 19 points. In the off-season, Brière filed for salary arbitration, which resulted in a one-year, $5 million contract that the Sabres agreed to on August 5, 2006.
The following season, Brière scored two hat tricks. His first came on December 5, 2006, against the Tampa Bay Lightning's goaltender Marc Denis. His second came shortly after, on January 30, 2007, in front of a home crowd at HSBC Arena in a 7–1 victory against the Boston Bruins, with two goals against Hannu Toivonen and one against his replacement Tim Thomas. He was voted in as a starter to his first NHL All-Star Game in Dallas, Texas, and recorded a game-high five points (one goal, four assists). He was named All-Star Game MVP and received a Dodge Nitro that he ended up giving to his sister. Brière finished the season with a career-high 32 goals, 63 assists and 95 points. He added 15 points in the post-season as the Sabres made their second straight appearance in the conference finals, but were eliminated by the Ottawa Senators.
As Brière's one-year contract expired at the end of 2006–07, he became an unrestricted free agent on July 1, 2007. It was widely speculated that Brière would return to his home province and play for the Montreal Canadiens, but he instead signed with the Philadelphia Flyers, who finished the previous season as the worst team in the NHL, to an eight-year, $52 million contract with a no-trade clause. The Flyers front-loaded the deal, paying Brière $10 million in the first season of the contract, making him the highest paid player of the league in 2007–08, along with Scott Gomez of the New York Rangers and former Sabres teammate Thomas Vanek. His decision to join the Flyers is often attributed to the influence of his friend Martin Biron, who was traded from Buffalo to Philadelphia at the previous season's trade deadline. He later cited the prospect of anonymity in Philadelphia as opposed to Montreal as an additional factor in his decision.
Brière's production dipped in his first season with the Flyers in 2007–08, but he still finished second in team scoring with 72 points in 79 games, behind eventual team captain Mike Richards. He scored his third career hat trick near the beginning of the season on November 21, 2007, against the Carolina Hurricanes's goaltender Cam Ward. Led by Brière and Richards on the newly revamped Flyers (additional off-season acquisitions included Kimmo Timonen, Scott Hartnell and Joffrey Lupul), Philadelphia went from worst team in the NHL the previous season to an appearance in the 2008 conference-finals against eventual Eastern Conference champions, the Pittsburgh Penguins. Brière recorded nine goals and seven assists in his third straight semi-finals appearance.
Less than a month into the 2008–09 season, on October 22, Brière suffered another abdominal tear requiring surgery. He was expected to be sidelined at least a month, but returned within half that time on November 8 against the Tampa Bay Lightning. In the next game, however, against the New York Islanders on November 11, he suffered a groin pull, sidelining him for nine games. In his first game back, Brière suffered yet another setback; he re-injured his groin on December 3 against the Tampa Bay Lightning. Preparing to make a return to the Flyers lineup, he was assigned to the Philadelphia Phantoms of the AHL on January 13, 2009, to play three games on a conditioning basis. Brière finished the season having played in just 29 games for the Flyers, recording 11 goals and 14 assists. The Flyers were eliminated for the second consecutive year in the playoffs by the Pittsburgh Penguins, the eventual Stanley Cup champions. Brière scored one goal along with three assists in the series.
The following season, Brière was suspended by the NHL for two games for leaving his feet to check Colorado Avalanche defenceman Scott Hannan, making contact with Hannan's neck with his elbow during a game on November 23, 2009. He also suffered a tweaked groin during that season and missed five games because of it. However, a highlight came to Brière on February 13, 2010, in a game in Montreal where he scored a hat trick with all goals in different situations: power-play, even strength and penalty shot against Carey Price.
Brière led the entire 2010 Stanley Cup playoffs in scoring with 30 points (12 goals and 18 assists) and in the process broke the record for points in a post-season by a Flyer, held previously by Brian Propp, who had 28 in 1987. Five games into the playoffs, he was placed with wingers Scott Hartnell and Ville Leino, where the line went on to be one of the most effective of the post-season. In the 2010 Stanley Cup Final series alone, Brière finished with 12 points (three goals and nine assists), one point shy of Wayne Gretzky's record of 13 in a final, and the highest output in a final since Mario Lemieux in 1992.
During the last minute of an October 30, 2010, game against the New York Islanders, Brière was given a five-minute cross-checking major and a game misconduct for a stick-swinging incident with Frans Nielsen. On November 1, the NHL suspended Brière for three games. Brière disagreed with the ruling, saying, "If you look at the replay, it's clearly not a crosscheck which is two hands moving forward. It's a push with one hand. The mistake I made is my stick was up there. Is it worth three games for that? I don't think so. And on top of that, I missed him. I didn't even get him... My glove grazed the top of his helmet, not my stick."
On January 19, 2011, Brière was named as the replacement to play in the All-Star Game for Calgary Flames player Jarome Iginla, who cited health concerns about his grandmother as the reason for dropping out of what would have been his sixth All-Star appearance. Brière scored two goals for Team Lidstrom in the game, helping them to an 11–10 victory over Team Staal. Brière finished the 2010–11 NHL season with 34 goals and 34 assists. He went on to record seven goals during the 2011 Stanley Cup playoffs, a post-season that saw the Flyers defeat Brière's former team, the Buffalo Sabres, in seven games but fall to the eventual Stanley Cup champion Boston Bruins in a four-game sweep.
On January 7, 2012, Brière scored his fifth hat trick as well as his third NHL fight (against Kyle Turris) on home ice. His third goal, against Craig Anderson, was the game winner in overtime as the Flyers beat the Ottawa Senators by a 3–2 score, Brière having scored all of the Flyers' goals. During the 2012 Stanley Cup playoffs, Brière continued his dominant playoff play, scoring eight goals in 11 games as the Flyers eventually fell to the New Jersey Devils, the eventual Eastern Conference Champions, in five games in the second round.
During the 2012–13 NHL lockout, Brière and Flyers teammate Claude Giroux played for Eisbären Berlin of the German Deutsche Eishockey Liga (DEL). Brière played in a total of 21 games before being injured by an uncalled slash of his wrist which resulted in hyperextension and a bone bruise.
On June 18, 2013, Brière was informed by Flyers management that he would be given a compliance buyout, ending his tenure with the Flyers.
On July 4, 2013, Brière signed a two-year, $8 million contract with the Montreal Canadiens. On October 19, 2013, Brière sustained another concussion against the Nashville Predators after a collision with Eric Nystrom, which sidelined him for almost a month before returning to the lineup on November 12, 2013. Brière returned to the Wells Fargo Center in Philadelphia on December 12, 2013, and was greeted with a standing ovation by the home crowd.
On June 30, 2014, Brière was traded to the Colorado Avalanche in exchange for P. A. Parenteau and a fifth-round draft pick in 2015. Briere's movement has been accredited to him not wanting to play in Montreal anymore.
Following the conclusion of the 2014–15 season, Brière was not re-signed by the club, and on August 17, 2015, he announced his official retirement from professional hockey.
Brière appeared in the 1994 Ivan Hlinka Memorial Tournament, a highly competitive under-18 event not directly sanctioned by the International Ice Hockey Federation (IIHF). He scored five points and earned his first gold medal as Canada defeated the United States 5–2 in the final. Three years later, during his final year of major junior in the Quebec Major Junior Hockey League (QMJHL), he competed for Team Canada at the 1997 World Junior Championships in Switzerland. Brière scored six points in seven games and captured his second gold medal, defeating the United States once more 2–0.
Brière debuted at the senior level with Team Canada at the 2003 World Championships and scored nine points in nine games. He earned another gold medal, defeating Sweden in the final. The next year, at the 2004 World Championships, Brière earned his fourth gold medal in as many international appearances, again topping Sweden 5–3 in the final. He tallied eight points to finish ninth in tournament scoring.
Growing up, Brière attended Collège Saint-Alexandre, a private high school in Gatineau. He has three sons- Caelan (born July 1998); Carson (born September 1999); and Cameron (born April 2001) – with ex-wife Sylvie and has been a resident of Haddonfield, New Jersey.
Brière had fellow Flyer Claude Giroux as a housemate in 2011; when Giroux moved out after the 2011 season, Flyers rookie and fellow French-Canadian Sean Couturier moved in.Named Top Forward at the 1994 Air Canada Cup
Michel Bergeron Trophy (rookie of the year) – 1995
Marcel Robert Trophy (scholastic player of the year) – 1995
QMJHL All-Rookie Team – 1995
Jean Beliveau Trophy (leading scorer) – 1996
QMJHL Humanitarian of the Year – 1996
Ford Cup (offensive player of the year) – 1996
QMJHL Second All-Star Team – 1996, 1997
Frank J. Selke Memorial Trophy (most sportsmanlike player) – 1997
Rookie of the Month – October 1997
Dudley "Red" Garrett Memorial Award (rookie of the year) – 1998
Played in the All-Star Game in 2007 (starter)
Named the All-Star Game MVP in 2007
Led all players in points during the 2010 Stanley Cup playoffs – 30
Played in the All-Star Game in 2011