Sam Reinhart was selected by the Buffalo Sabres with the No. 2 pick in the 2014 NHL Draft after he had 105 points (36 goals, 69 assists) in 60 games for Kootenay and won the Four Broncos Memorial Trophy as the most valuable player in the Western Hockey League.

Although Reinhart began the 2014-15 season with Buffalo, after he had one assist in nine games, he was returned to Kootenay, where he finished with 65 points (19 goals, 46 assists) in 47 games.

Reinhart returned to the Sabres for good the following season, when he scored 23 goals and had 42 points in 79 games as a rookie.

He continued to build upon his offensive totals, getting 47 and 50 points, respectively, in each of the following two seasons before breaking out in 2018-19, when he set then-NHL career highs in assists (43) and points (65) in 82 games.

That strong play continued in 2019-20, when he had 50 points (22 goals, 28 assists) in 69 games before the season was paused March 12 due to concerns surrounding the coronavirus. Reinhart played seven seasons with the Sabres, and on July 24, 2021, was traded to the Florida Panthers for goalie prospect Devon Levi and a first-round pick in the 2022 NHL Draft.

He scored his 25th power-play goal of the 2023-24 season in Florida's 4-2 win at the New York Rangers on March 4 to become the sixth skater in the past 20 years to reach the mark in one season, joining Leon Draisaitl (32 in 2022-23), Chris Kreider (26 in 2021-22), Alex Ovechkin (25 in 2014-15), Teemu Selanne (25 in 2006-07) and Ilya Kovalchuk (27 in 2005-06). He was also the second player in NHL history with at least 25 goals on the man-advantage and five short-handed goals in the same season after Mario Lemieux in 1988-89 and 1995-96.

Reinhart scored his 50th goal of 2023-24 in Florida's 4-1 win against the Philadelphia Flyers at Wells Fargo Center on March 24, 2024. He was the second Panthers player to score 50 goals, joining Pavel Bure, who scored 58 in 1999-2000 and 59 in 2000-01. He finished with 57, second in the NHL behind Toronto Maple Leafs forward Auston Matthews (69), and had 10 in the playoffs to become a Stanley Cup champion for the first time. Reinhart was the fourth player in NHL history with 50 goals in the regular season and the Stanley Cup-clinching goal (Jari Kurri, Edmonton Oilers, 1987; Mike Bossy, New York Islanders 1982 and '83; Guy Lafleur, Montreal Canadiens, 1976).

Reinhart signed an eight-year contract with the Panthers on July 1, 2024. He was named to Canada's roster for the 4 Nations Face-Off during the 2024-25 season, his four goals in a 5-1 win against the Oilers in Game 6 of the Stanley Cup Final tied the record for most in a Cup Final game (Babe Dye for the Toronto St. Patricks in 1922) and he became the second player in NHL history with four goals in a Cup-clinching win. He also had the first four-goal game and hat trick in Panthers playoff history, and was the first player since Wayne Gretzky in 1985 to score seven goals in the championship round.

Reinhart helped Team Canada win silver at the Olympic Winter Games Milano Cortina 2026.

Reinhart's brothers, Max and Griffin, each briefly played in the NHL, and his father, Paul, was a defenseman who had 559 points (133 goals, 426 assists) in 648 games over 11 NHL seasons with the Atlanta Flames, Calgary Flames and Vancouver Canucks.