[2] He was called up to the Golden Knights on January 10, 2020, and made his NHL debut the following night against the Blue Jackets.

[3][4] On March 22, 2021, Kolesar scored his first NHL goal in the third period of the Golden Knights 5–1 win against the St. Louis Blues.

[5] On June 13, 2023, Kolesar won his first Stanley Cup, with Vegas defeating the Florida Panthers 9-3 to win their first championship in franchise history.

[8] Kolesar was born on April 8, 1997, in Brandon, Manitoba[9] to former NFL and CFL linebacker K. D. Williams and Corrinne.

The parents divorced following his birth and Corrinne remarried to Charles Peterson who played for the Kansas City T-Bones of the Northern League.