Prior to playing in the NHL, Giroux played his major junior career with the Gatineau Olympiques of the Quebec Major Junior Hockey League (QMJHL), where he helped the team win a 2008 President's Cup and earned the Guy Lafleur Trophy as the 2008 playoff MVP. Internationally, he won a gold medal with Team Canada in the 2008 World Junior Ice Hockey Championships.
Giroux made his debut with the Flyers in February 2008 and joined the roster full-time midway through the 2008–09 season. In 2011, after the blockbuster trades of Mike Richards and Jeff Carter, Giroux took over the role of the club's first line centre. Giroux was the club's top point-scorer in the 2010–11, 2011–12 and 2013–14 seasons. In 2012 and 2014, Giroux finished third in the League in point-scoring.
Giroux grew up playing hockey in his hometown of Hearst, Ontario, and played Bantam A for the Hearst Lumber Kings (NOHA) in the 2001–02 season. In the summer of 2002, he and his family moved to the Ottawa, Ontario suburb of Orleans. In Orleans, Giroux played Major Bantam AA and Minor Midget AA for the Cumberland Barons, and was the club's leading scorer in the 2002–03 and 2003–04 seasons. Eligible for the 2004 Ontario Hockey League (OHL) draft, Giroux entered but went undrafted. In the 2004–2005 season, Giroux played for the Cumberland Grads. Despite missing most of the season after contracting mononucleosis, Giroux scored 40 points in 48 games and was named Canadian Junior Hockey League (CJHL)'s Rookie of the Year. However, Giroux went undrafted once again at the 2005 OHL Draft.
A free agent, Giroux was invited to Gatineau Olympiques training camp for a walk-on tryout. He was signed shortly after. During his rookie season with the Olympiques, Giroux scored 39 goals for a total of 103 points in 69 games and was named Quebec Major Junior Hockey League (QMJHL)'s Rookie of the Year. He entered the 2006 NHL Entry Draft and was selected 22nd overall by the Philadelphia Flyers. The Flyers signed Giroux to an entry level contract on July 23, 2007.
Giroux made his NHL debut when the Flyers visited the Ottawa Senators on February 19, 2008, recording no points and being the team's first shooter in the shootout. Sent back down to the Olympiques, he helped the club win the QMJHL Playoffs and earned himself the Guy Lafleur Trophy as MVP in the QMJHL Playoffs by scoring 17 goals and 34 assists in 19 playoff games, also setting a franchise record.
After a disappointing training camp for the Flyers at the beginning of the 2008–09 season, Giroux was assigned to the team's American Hockey League (AHL) affiliate, the Philadelphia Phantoms. After acclimatizing to professional hockey, however, things turned around quickly; he was named Rookie of the Month for December for his eight goals and six assists in eight games played. He was then called up to the Flyers after the Christmas break and remained there throughout the rest of the season. On December 31, he recorded his first NHL point by assisting on a Jeff Carter goal in a win over the Vancouver Canucks. He suffered a mild concussion during the next game when Corey Perry of the Anaheim Ducks elbowed him in the head. Giroux finished the game but missed the next five; Perry was suspended for four games.
On January 27, 2009, Giroux scored his first NHL goal against goaltender Tomáš Vokoun and the Florida Panthers in a 3–2 loss. His first Stanley Cup playoff goal came in a 6–3 win in Game 3 of the 2009 Eastern Conference Quarterfinals against Marc-André Fleury of the Pittsburgh Penguins. The same game also saw him setting up a short-handed goal when he stole the puck in the corner of the Penguins zone and outworked their backcheck, skating past the back of their net twice protecting the puck while looking for incoming support in the form of Simon Gagné. Giroux ended the 2008–09 season with nine goals and 27 points in 42 games played.
The Flyers were an inconsistent team for the bulk of the 2009–10 season, which affected all of their players. Giroux spent a large amount of time centring James van Riemsdyk, the highly touted rookie winger that the Flyers had drafted second overall in 2007. The Flyers' fortunes, however, soon turned dramatically: they qualified for the 2010 playoffs on Giroux's game-winner in a shootout against the New York Rangers. Giroux was a major point producer in a first round of the playoffs, dismantling the second-seeded New Jersey Devils. The Flyers made an historic comeback from three games to none down against the Boston Bruins to win the next four and advance to the Eastern Conference Finals, where they dominated the Montreal Canadiens. Giroux scored the winning goal in overtime against the Chicago Blackhawks in Game 3 of the 2010 Stanley Cup Finals, but despite his continued production, the Flyers eventually lost in overtime in Game 6 of the Finals. Giroux ended the post-season with 21 playoff points, cementing his reputation as an emerging young talent.
A month into the 2010–11 season, the Flyers signed Giroux to a three-year, $11.25 million contract extension. The contract, which was signed on November 8, 2010, accounted for a $3.75 million cap hit annually. On January 11, 2011, Giroux was named to the 2011 NHL All-Star Game roster. He finished his break-out season with 25 goals and 51 assists in 82 games and scored a goal and 11 assists in 11 2011 playoff games, in which the Flyers defeated the Buffalo Sabres but were ultimately defeated by the Bruins. Giroux played his 200th career game on March 26, 2011, against the New York Islanders.
After the Flyers traded away Jeff Carter and Mike Richards in the 2011 off-season, Giroux took over the role as first line centre for the club. The trading of Richards and Carter also made him the second-longest tenured member of the Flyers. Giroux formed a new top line with Scott Hartnell and free agent acquisition Jaromír Jágr. Giroux led the League in point-scoring for much of the season, and was considered a favourite for the Hart Memorial Trophy for League MVP at the season's All-Star break. He finished the season, however, 16 points behind eventual Hart Trophy winner Evgeni Malkin. On April 13, 2012, Giroux recorded his first career hat trick during game two of the first round of the 2012 playoffs against Pittsburgh. He recorded six points during that same game, earning a Flyers record for most points during a single Stanley Cup playoff game. On May 7, 2012, Giroux received a one-game suspension for a hit to the head of New Jersey Devils forward Dainius Zubrus during Game 4 of the Eastern Conference Semifinals. After the Flyers were eliminated by the Devils, Giroux ended the season as both the Flyers' top regular season point-scorer (93 points) and top playoff point scorer (17 points). After the Flyers' elimination, Giroux had surgery on both of his wrists; the right to repair torn cartilage, and the left to remove bone spurs. He later claimed that Sidney Crosby had repeatedly slashed his wrists during face-offs in the first round series against Pittsburgh. At the time news of the surgery was revealed, Giroux was still the playoffs' leading point scorer, even though his team had been eliminated two weeks earlier. On June 20, 2012, Giroux was named the cover athlete for NHL 13 at the NHL awards in Las Vegas; he became the first Philadelphia Flyer on an EA Sports NHL video game cover since Eric Lindros on NHL 99.
During the 2012–13 NHL lock-out, Giroux and Flyers teammate Daniel Brière played for Eisbären Berlin of the German Deutsche Eishockey Liga (DEL). In his ninth game in Germany, he suffered a neck and shoulder injury that was initially feared to be a concussion. He returned to North America and remained inactive through the remainder of the lock-out. After the lock-out ended, Giroux was named the 19th team captain in Flyers history on January 15, 2013, taking over for the indefinitely-injured Chris Pronger.
Giroux got off to a slow start once the shortened 2012–13 season began. Missing linemates Jaromír Jagr, who signed with the Dallas Stars during free agency, and Scott Hartnell, who suffered a broken foot during the third game of the season, Giroux registered only seven points through the team's first 13 games. His season turned around once right winger Jakub Voráček, who was also struggling, was placed on his line. From February 12 through the end of the regular season, Giroux was the fourth-most productive player in the League, scoring ten goals and 30 assists for a total of 40 points during that span. He finished with 48 points in 48 games and new linemate Voráček finished with a career-high 22 goals. The team as a whole struggled, however, and the Flyers missed the playoffs for the first time since the 2006–07 season.
On July 5, 2013, Giroux signed an eight-year, $66.2 million contract extension to stay in Philadelphia.
The entire Flyers team struggled out of the gate, as Philadelphia won just one of their first eight games. Giroux was no exception, and had a difficult start to the 2013–14 season. In his first 15 games, he put up just seven assists and failed to tally a goal. Eventually, the team's struggles ran their course and the Flyers' and Giroux's play seemed to revert to normal.
Giroux's year took another turn when it came down to the Olympic roster selection. He was one of the biggest names left off of the Canadian team. But since that point, Giroux picked up his play. As of April 12, he was third in the league in points and the Flyers were in third place in the Metropolitan Division. At the conclusion of the season, Giroux was nominated for the NHL's Hart Trophy and the Ted Lindsay Award, both of which he lost to Sidney Crosby.
Giroux competed with Team Canada in the IIHF World Junior Ice Hockey Championship in 2008. He scored two goals and four assists in seven games to help Canada win its fourth consecutive WJC. He competed with Team Canada in the IIHF World Championship in April 2013. He scored three goals and five assists in eight games. In 2015, he was a member of Canada's gold medal-winning team at the World Hockey Championships.
Giroux was born on January 12, 1988, in Hearst, Ontario to Raymond and Nicole Giroux. He has one sister, Isabelle. He attended Béatrice-Desloges High School in Orléans, Ontario. His nickname is G.
During the 2010–2011 season, Giroux lived with teammate Daniel Brière and Brière's three sons in their Haddonfield, New Jersey home. In 2011, Giroux moved out and into an apartment with teammate Brayden Schenn.
On July 1, 2014, Giroux was taken into custody by police in Ottawa after twice grabbing the buttocks of a male police officer while intoxicated inside an Ottawa nightclub. Though he reportedly spent the night in jail, no charges were laid.
In December 2016, Giroux became engaged to longtime girlfriend Ryanne Breton.Gatineau Olympiques – 51 points in 19 playoff games
Philadelphia Flyers – Most points in a single Stanley Cup playoffs game (6)
Played in the 2005–06 CHL Top Prospects Game
QMJHL Rookie of the Month – December 2005 and March 2006
2005–06 QMJHL All-Rookie Team
QMJHL Offensive Player of the Month – September 2006
2008 President's Cup (QMJHL playoff champion) with Gatineau Olympiques
2008 Guy Lafleur Trophy (QMJHL playoff MVP)
2007–08 QMJHL First All-Star Team
2007–08 Canadian Major Junior First All-Star Team
AHL Rookie of the Month December 2008
Prince of Wales Trophy with the Philadelphia Flyers – 2010
Played in the NHL All-Star Game in 2011, 2012, 2015, and 2016
Bobby Clarke Trophy – 2011, 2012, 2014, 2016
Toyota Cup (3 Stars Award) – 2012, 2013, 2014, 2015, 2016
Named 2011 Pro Athlete of the Year by the Philadelphia Sports Writers Association
2012 recipient of the Philadelphia Sports Congress' John Wannamaker Athletic Award
Voted in as the cover athlete for EA Sports' NHL 13 video game
Game-winning goal against the Columbus Blue Jackets voted by fans as the team's "Highlight of the Year" during the 2013–14 season
Game-winning overtime goal against the Winnipeg Jets, along with the assist by Shayne Gostisbehere, voted by fans as the team's "Highlight of the Year" during the 2015–16 season