Major junior in 2016 Nylander was selected 12th overall by the
Mississauga Steelheads of the
Ontario Hockey League (OHL) at the 2015
Canadian Hockey League (CHL) Import Draft. On 5 September 2015, Nylander committed to the Steelheads with his father joining as assistant coach. His reasons for joining include being close to his brother
William and having the chance to play the Canadian style of hockey. In his only season with the Steelheads, Nylander led all rookies in scoring, and was awarded both the
Emms Family Award as OHL Rookie of the Year and
CHL Rookie of the Year. Leading up to the NHL draft, Nylander was ranked the no. 3 North American skater. He was described as a dynamic offensive player with a great shot and playmaking ability.
Professional Nylander was selected eighth overall by the
Buffalo Sabres of the
National Hockey League (NHL) in the
2016 NHL entry draft. On 15 July 2016, the Sabres signed Nylander to a three-year entry-level contract. Nylander was called up to the NHL for the first time on 3 April 2017, to play in a game against the
Toronto Maple Leafs. Nylander played 14:28 minutes during the 4–2 loss. Nylander suffered a lower-body injury in mid-September during the Buffalo Sabres' first prospect game, causing him to miss the rest of the training camp and the beginning of the 2017–18 AHL season. He returned to the lineup on 17 November 2017, for a game against the
Hartford Wolf Pack. Despite a slow start, Nylander was called up to the NHL on 3 April 2018. He recorded his first career NHL goal on 6 April 2018 in a game against the
Tampa Bay Lightning. After the Sabres failed to qualify for the
2018 Stanley Cup playoffs, Nylander was reassigned to the AHL. On 9 July 2019, Nylander was traded by the Sabres to the
Chicago Blackhawks in exchange for fellow first-rounder
Henri Jokiharju and opted to wear sweater no. 92 with the club, the same number his father wore. Nylander appeared in 65 games during the condensed
2019–20 season for the Blackhawks, where he recorded 10 goals and 16 assists. Nylander appeared in eight postseason games for Chicago but failed to register a point. Beginning the
2021–22 season on the injured reserve, Nylander missed the first half of the season. On returning to health, Nylander was traded to the
Pittsburgh Penguins, in exchange for
Sam Lafferty on 5 January 2022. In the midst of the
2023–24 season, having split time between Wilkes-Barre/Scranton and Pittsburgh for the third successive season, Nylander was traded following five games with the Penguins, along with a conditional 2026 sixth round pick to the Columbus Blue Jackets in exchange for
Emil Bemström on 23 February 2024. Instantly joining the Blue Jackets, Nylander made his debut with Columbus in a 4–2 victory over the
New York Rangers on 25 February 2024, and recorded his first NHL
hat trick in a 6–3 win against the
Vegas Golden Knights on 4 March 2024. In an elevated offensive role with the Blue Jackets, Nylander responded in notching a career best 11 goals through just 23 games to close out the season. As a free agent from the Blue Jackets at the conclusion of his contract, Nylander was unable to secure an NHL deal and opted to sign a one-year AHL contract with the
Toronto Marlies of the AHL, affiliate to the Toronto Maple Leafs on 28 July 2024. Nylander began the
2024–25 season, posting 8 goals and 12 points in 14 appearances with the Marlies. With the Maple Leafs suffering a spate of injuries, he was signed to a one-year league minimum contract and instantly recalled to the Maple Leafs on 22 November. Nylander was assigned to the Toronto Marlies after he cleared waivers on 12 December. He would play 5 games with the Maple Leafs but spend the majority of the season with the Toronto Marlies, after which he was not resigned to a new contract and released to unrestricted free agency. On 4 August 2025, Nylander opted to remain within the Maple Leafs organization after going un-signed over the summer, agreeing to a one-year AHL contract with the Marlies for the
2025–26 season. ==International play==