Dylan Cozens authored a signature moment early in his NHL career when he scored 12 seconds into overtime to give the Buffalo Sabres a 3-2 win against the New York Islanders at KeyBank Center on Jan. 19, 2023, his goal coming on a breakaway and hours after the Sabres retired the No. 30 of former goalie Ryan Miller and inducted him into the Buffalo Sabres Hall of Fame.

Afterwards, Cozens gave the game-winning stick to Miller's son, Bodhi. A few weeks later, the native of Whitehorse, the capital of Yukon, signed a seven-year, $49.7 million contract with Buffalo on Feb. 7, his NHL career trending upwards with 17 goals and 43 points in 49 games that eclipsed his previous career-bests of 13 goals and 29 assists he set in 79 games of the 2021-22 season.

Cozens' breakthrough 2022-23 NHL season continued with his first NHL hat trick and four-point game in a 7-4 win against the Washington Capitals on Feb. 26. At 22 years and 17 days, he became the youngest player since Jack Eichel (21 years, 48 days; Dec. 15, 2017) to score three goals in a game for Buffalo.

He was traded to the Ottawa Senators on March 7, 2025.

Cozens became the first player from Yukon selected in the first round of the NHL Draft when the Buffalo Sabres made him the No. 7 pick in 2019 and he has developed into a big part of the future in Buffalo. After four seasons with Lethbridge of the Western Hockey League, the forward made his NHL debut Jan. 14, 2021 and got his first NHL point (an assist) in a 6-4 loss to the Washington Capitals. Cozens ended his rookie season with 13 points (four goals, nine assists) in 41 games, including seven assists in eight games from April 11-23.

Cozens helped Canada win the 2020 IIHF World Junior Championship with a goal in a 4-3 victory against Russia in the title game. He and Colorado Avalanche defenseman Bowen Byram were co-captains at the 2021 WJC after forward Kirby Dach left the tournament with an injury. Cozens scored 16 points (eight goals, eight assists) in seven games and Canada reached the championship game but lost 2-0 to the United States. Cozens' point total was tied for the fifth highest by a Canada player in WJC history, behind Dale McCourt (18 points, 1977), Brayden Schenn (18 points, 2011), Wayne Gretzky (17 points, 1978) and Eric Lindros (17 points, 1991).

Cozens had an assist in his NHL debut, a 6-4 loss to the Washington Capitals on Jan. 14, 2021.