On April 20, 2022, Vanacker was drafted 23rd overall by the Hamilton Bulldogs in the 2022 OHL Draft.[1] On May 21, 2022, he signed with the Bulldogs.[2] During the 2022–23 season, he recorded four goals and 12 assists in 55 games for the Brantford Bulldogs. During the 2023–24 season, he recorded 36 goals, 46 assists, 22 power-play points and five short-handed goals in 68 regular season games for the Bulldogs. He led the team in goals and points, and ranked second in assists. During the playoffs he recorded three goals and four assists in six games.[3]
On June 28, 2024, Vanacker was drafted 27th overall by the Chicago Blackhawks in the 2024 NHL entry draft.[4][5] He was signed to a three-year, entry-level contract with the Chicago Blackhawks on August 5, 2024.[6]