Guillemette played college football for the Holy Cross Crusaders from 2019 to 2022.

[4] Guillemette made his professional debut in the team's season opener on June 18, 2023, against the Hamilton Tiger-Cats.

[5] He played in all 18 regular season games as well as the team's East Final loss to the Montreal Alouettes.

[6] In 2024, Guillemette played in 17 regular season games while sitting out one due to injury.

[2] He also played in all three post-season games, including the 111th Grey Cup where the Argonauts defeated the Winnipeg Blue Bombers 41–24 and he won his first Grey Cup championship.