Selected by his hometown Ottawa Senators in the 2011 NHL Entry Draft, Pageau began his professional career in 2012–13 with Ottawa's American Hockey League (AHL) affiliate, the Binghamton Senators, registering 7 goals and 29 points in 69 games before being called-up to Ottawa on April 10, 2013.[2] Pageau stayed in Ottawa for the remainder of the season, registering two goals and four points in nine regular season games. On May 5, 2013, he scored a hat-trick in Game 3 of the Eastern Conference Quarterfinals series as the Senators defeated the Montreal Canadiens 6–1. In so doing, he became just the second Senators player to score a hat-trick in the playoffs after Daniel Alfredsson.[3]
Following the season, Pageau was honoured by his hometown; on June 18, 2013, he signed the official guestbook at the start of the Gatineau City Council meeting and received a plaque. Mayor of Gatineau Marc Bureau called him "a true ambassador for the city".[4]
Pageau would only appear in parts of the 2013–14 and 2014–15 seasons under head coach Paul MacLean. Upon MacLean being fired, new head coach Dave Cameron would allow Pageau to play more games during the 2014–15 season, including all six of the Senators' 2015 playoff games. In June 2015, it was announced Pageau signed a two-year, one-way contract with the Senators worth an annual average of $900,000.[5] Pageau would play in all 82 games during the 2015–16 season and achieve career highs in goals (19), assists (24) and points (43), and led the NHL in short-handed goals with seven.[6] Pageau scored four goals in Game 2 of round two of the 2017 playoffs against the New York Rangers, including the game-winner in double overtime.[7]
On July 17, 2017, Pageau signed a new three-year, $9.3 million contract worth $3.1 million annually, avoiding arbitration.[8]
In the final year of his contract with the Senators in the 2019–20 season, Pageau emerged as the club's top line center, scoring at a career high pace with 24 goals and 40 points in 60 games.
New York Islanders
With the Senators out of playoff contention and as a potential free agent, Pageau ended his eight-year tenure with Ottawa when he was traded to the New York Islanders at the NHL trade deadline in exchange for a conditional first-round pick and a second-round pick in 2020 and a conditional third-round selection in 2021.[9] He was immediately signed to a six-year, $30 million contract extension to remain with the Islanders through 2026.[10] In his debut with the Islanders on February 25, he received a 10-minute game misconduct, scored his NHL career-high 25th goal of the season, and skated 12:07 on the third line with Josh Bailey and Michael Dal Colle.[11][12] Prior to the NHL's pause in play due to the ongoing COVID-19 pandemic, the Islanders had failed to qualify for the 2020 Stanley Cup playoffs as they lost seven straight games leading up to March 12.[13] However, they were made eligible for the newly created Stanley Cup Qualifiers when the NHL resumed play.[14] Over the lengthy pause, Pageau returned to Ottawa to spend quarantine until the NHL resumed play.[15]
Pageau checking Seattle Kraken player Jamie Oleksiak in 2023.
Pageau and the Islanders met with the Florida Panthers in the Eastern Conference Qualifying Round. Pageau played an important role for the Islanders during their series against the Panthers. He scored the first goal of Game 1 against the Panthers and won 80 percent of his faceoffs while skating in all situations including the power play and penalty kill.[16] Throughout the first three games against the Panthers, Pageau played on a line with Tom Kuhnhackl and Derick Brassard before Kuhnhackl was replaced by Leo Komarov.[17] As the Islanders eliminated the Panthers, Pageau ended the series tied for the team lead in goals with Anthony Beauvillier.[18] He also finished the series logging the most time shorthanded time of ice among Islanders forwards with a total of 8:19 and played 7:38 on the power play.[17] Following their series win, the Islanders faced off against the Washington Capitals in the Eastern Conference First Round.[19] As Pageau remained on a line with Brassard and Komarov through the Capitals series, they helped push the Capitals to the brink of elimination by winning the first three games of the series.[20] Despite an attempted comeback, the Islanders eliminated the Capitals in five games to advance to the Second Round.[21] The Islanders then faced the Philadelphia Flyers whom they eliminated in seven games to advance to the Eastern Conference Final for the first time since 1993.[22] During their Eastern Conference Final series against the Tampa Bay Lightning, Pageau was moved onto a line with Matt Martin and Cal Clutterbuck in Game 3 and 4 after Komarov and Casey Cizikas were injured.[23]
On March 25, 2021, Pageau recorded his 100th career goal in a 4–3 win over the Boston Bruins.[24] On August 7, Pageau was voted the winner of the Bob Nystrom Award for the 2020–21 season.[25]
International play
On April 12, 2018, Pageau was one of the 18 players to be named to the 2018 IIHF World Championship to represent Canada, where he scored one goal and tallied three assists.[26][27]
Canada
