Hayton signed a two-year contract with the Arizona Coyotes on Sept. 20, 2022, after he had 24 points (10 goals, 14 assists) in 60 games the prior season, earning praise from general manager Bill Armstrong as "a young, talented, hard-working player who made significant strides." He signed a two-year, $5.3 million contract as a restricted free agent with the Utah Hockey Club on July 8, 2024.

Hayton's road to the NHL began in his native Peterborough, Ontario, while his father, Brian Hayton, was a defenseman for Guelph of the Ontario Hockey League. Barrett Hayton played minor midget hockey with the Peterborough Petes and Toronto Red Wings, and the Upper Canada College team as a student. He had 73 points (36 goals, 37 assists) in 59 games as a 15-year-old with the Red Wings and was chosen by Sault Ste. Marie with the No. 9 pick in the 2016 OHL Draft. After agreeing to a contract with the Greyhounds on June 17, 2016 to start his major junior career, he had 27 points (nine goals, 18 assists) in 63 games during his rookie season and progressed to nearly a point-per-game pace with 60 points (21 goals, 39 assists) in 63 games to win the Bobby Smith Trophy as the OHL Scholastic Player of the Year. Hayton had 16 multipoint games and a season-high seven-game point streak (nine points; three goals, six assists) from Oct. 11-28.

The Coyotes saw enough to select Hayton with the No. 5 pick in the 2018 NHL Draft and signed him to a three-year, entry-level contract July 6, 2018. He started the 2018-19 season with Arizona but was a healthy scratch the first two games and was named Sault Ste. Marie captain upon his return to juniors. That season, Hayton set OHL career highs of 26 goals, 40 assists and 66 points in 39 games, with a career-high 1.69 points per game that was second on the team and third in the league.

Hayton became the seventh-youngest Coyotes player (19 years, 123 days) to make his NHL debut Oct. 10, 2019, when he had his first NHL point with a secondary assist on Nick Schmaltz's first-period goal in a 4-1 win against the Vegas Golden Knights. His first NHL goal was a game-winner against Mackenzie Blackwood of the New Jersey Devils on Oct. 25. Hayton was later named Canada's captain for the 2020 IIHF World Junior Championship, where he had 12 points (six goals, six assists) in seven games en route to a first-place finish.