Mathieu Choinière

CF Montréal

Choinière signed an MLS contract with the Montreal Impact, later renamed CF Montréal, on July 17, 2018. He made his first appearance the next day against the Vancouver Whitecaps FC in the Canadian Championship. He made his first league appearance 3 days later against the Portland Timbers. Choinière would have his option for the 2020 season exercised by the Impact, keeping him with the club. In February 2022 Choinière signed a contract extension through 2024, with an option year for 2025. In June 2023, he was named to the 2023 MLS All-Star Game team after a standout first half of the season. During the 2024 season, Choinière was once again named an MLS All-Star.

Grasshoppers

On August 27, 2024, Choinière made the jump into European football, signing a three-year contract with Swiss Super League side Grasshoppers. He made his debut for his new club on September 21, 2024, against Servette, and scored the first goal in an eventual 2–2 draw.

Los Angeles FC

On July 28, 2025, he was loaned to Grasshoppers' parent club Los Angeles FC until the end of 2025. On December 9, 2025, LAFC exercised their buy option to sign Choinière permanently.

Youth

Choinière has been called up to various youth camps for Canada. In 2017, he was called up to a Quebec-Canada U20 team to play friendlies against Haiti U20, who were preparing for the 2017 Jeux de la Francophonie. In May 2018, he was called up to the Canada U21 team for the 2018 Toulon Tournament. He scored a goal against France in the fifth-place playoff. In October 2018 Choinière was named to the Canadian Under-20 squad for the 2018 CONCACAF U-20 Championship. He scored in Canada's second game of the tournament against Guadeloupe. Choinière was named to the Canadian U-23 provisional roster for the 2020 CONCACAF Men's Olympic Qualifying Championship on February 26, 2020.

Senior

In November 2022, Choinière received his first call-up to the Canadian senior side for a friendly against Bahrain, but did not feature in the match. On October 13, 2023, Choinière made his debut for Canada in a friendly against Japan, coming on as a substitute for Jonathan Osorio at the 61st minute. In June 2024, Choinière was named to Canada's 26-man squad for the 2024 Copa América. In May 2026, Choinière was selected for Canada's squad for the 2026 FIFA World Cup.

Choinière was born in Saint-Jean-sur-Richelieu, Quebec and grew up in the neighbouring Saint-Alexandre, Quebec. He began playing soccer with Celtix du Haut-Richelieu, before moving on to CS St-Hubert. In 2011, he joined the Montreal Impact Academy and became the first player in the organization's history to play for the U13, U14, U16, U18 and U19 teams prior to joining the first team.

Choinière is of Filipino descent. His older brother David is also a soccer player.