[3] As a child, he suffered from several health conditions including hand, foot, and mouth disease, several bouts of pneumonia due to respiratory syncytial virus, and recurrent ear infections, the latter of which required surgery to insert tympanostomy tubes.

[4] He befriended his neighbour Isaac Ratcliffe, and the two began playing sports together when they were eight: ice hockey in the winter, and golf and soccer in the summer.

[12] After finishing the first half of his rookie season with an overtime goal against the London Knights,[13] Suzuki scored his first OHL hat-trick on January 30, when Owen Sound defeated the Ottawa 67's 5–2.

[19] Entering the 2016–17 season, Suzuki, who had a goal and an assist in his first four games, was named a Player to Watch by the NHL Central Scouting Bureau.

[21] He was the top-ranked member of the Attack in the NHL Central Scouting Bureau's mideterm report, named the number 16 North American skating prospect.

[26] At the end of his sophomore season, Suzuki was named to the OHL Second All-Star Team,[27] and he also received both the William Hanley Trophy and the CHL Sportsman of the Year award after recording only 10 penalty minutes in 65 games.

[24] After his OHL season concluded, the Golden Knights assigned Suzuki to the Chicago Wolves, their American Hockey League (AHL) affiliate, for the team's Calder Cup run.

[40] On September 10, 2018, the Golden Knights traded Suzuki, as well as Tomáš Tatar and a second-round pick in the 2019 NHL Entry Draft, to the Montreal Canadiens in exchange for veteran forward Max Pacioretty.

Suzuki was named to the league's 2019 Third All-Star Team,[47] and likewise received his third consecutive William Hanley Trophy for recording just 12 penalty minutes over the course of the season.

[48] After sweeping the Kitchener Rangers in the first round of the 2019 OHL playoffs, during which Suzuki and Ratcliffe combined for six goals and 13 points,[49] Guelph quickly fell into a 3–0 series deficit against the London Knights.

[55] After making an impression on general manager Marc Bergevin during training camp, Suzuki was named to the Canadiens' opening-night roster for the 2019–20 season.

[58] Suzuki's first career NHL goal came in just his seventh game played, when he scored on Alex Stalock in a 4–0 shutout victory over the Minnesota Wild.

With this, he and defenceman Victor Mete became the first Montreal teammates to score their first career goals in the same game since Chris Higgins and Alexander Perezhogin in 2005.

[64] When the NHL returned to play for the 2020 Stanley Cup playoffs in July, Suzuki was one of 31 Canadiens selected to join the team in Toronto.

[65] He scored his first postseason NHL goal in the first game of the Stanley Cup qualifiers, putting Montreal up 2–0 in an eventual 3–2 win over the Pittsburgh Penguins.

[70] Starting the 2020–21 season on the top offensive line with Drouin and Josh Anderson,[71] Suzuki began the year on a six-game point streak.

[74] At the NHL trading deadline, Bergevin acquired veteran Eric Staal to act as a mentor for Suzuki and Jesperi Kotkaniemi, both of whom were struggling with consistency.

[75] Suzuki also benefited from the late-season addition of Cole Caufield, who joined the Canadiens after finishing his college ice hockey career with the Wisconsin Badgers.

[83] After defeating the Vegas Golden Knights in six games, Suzuki and the Canadiens faced the Tampa Bay Lightning in the 2021 Stanley Cup Finals.

[99] Although Montreal failed to reach the 2022 Stanley Cup playoffs,[100] Suzuki set career highs with 21 goals and 61 points, while his 209 consecutive games gave him the seventh-longest iron man streak among active players.

[103] Upon being named captain, several of the leading politicians in Quebec, including Coalition Avenir Québec Premier François Legault and Liberal leader Dominique Anglade urged Suzuki to learn French as a way to connect with the Montreal fans.

[104] Pittsburgh Penguins captain Sidney Crosby also privately advised him that he should do so, citing his own experience while playing in the Quebec Major Junior Hockey League (QMJHL) with the Rimouski Océanic.

[105] Suzuki told reporters that he took online classes during the summer as well as French in school growing up, but acknowledged he was currently better at reading the language than speaking it.

With Suzuki and Caufield an established duo on the team's first line, coach St-Louis began experimenting with different players in the other wing position.

[111] The team once again became plagued by injuries by the second half of the season, with Caufield being ruled out for the remainder due to shoulder surgery and Dach also missing time, before returning and resuming his position as second-line centre.

[119] Suzuki and Caufield had a rotation of wingers with them on the top line for the early part of the season, but the team's 2022 first overall draft pick, Juraj Slafkovský, gradually established himself as a regular presence with them.

[127] He was also the Canadiens' nominee for the King Clancy Memorial Trophy, which is awarded annually to the NHL player who "best exemplifies leadership qualities on and off the ice and who has made a noteworthy humanitarian contribution in his community," citing his charitable efforts.

[130] On December 21, Suzuki contributed two assists in a 5–1 win over the visiting Detroit Red Wings to surpass the 200 career threshold for this statistical category.

He provided three assists in five games, whereas his country was eliminated following a 2–1 quarterfinal loss to Finland, marking the first time in history that Canada had hosted the tournament and not reached the medal rounds.

[144] Suzuki began dating fellow Londoner Caitlin Fitzgerald during the 2016–17 OHL season, after connecting on social media while he was living in Owen Sound.