[10] On May 7, 2014, Gagnon-Laparé made his professional debut for the Montreal Impact in a 2–1 defeat to FC Edmonton in the Canadian Championship.

[14][15] In his debut season with the Impact, he assisted the club in winning the Canadian Championship and secured a berth in the 2014–15 CONCACAF Champions League.

[19][20] After trialing with Stade Rennais in late 2016,[21] Gagnon-Laparé signed with CFA club AS Vitré in January 2017.

[26] Following Ottawa ceasing operations and moving to Miami, Gagnon-Laparé stayed in the USL Championship with Saint Louis FC ahead of their 2020 season.

[28] On January 20, 2021, Gagnon-Laparé signed a two-year contract with an option for 2023 with Canadian Premier League side HFX Wanderers.

[30] Shortly after leaving the HFX Wanderers, Gagnon-Laparé signed with fellow CPL team York United on a two-year deal.

[32] On August 27, 2013, he received his first call up to the Canada national team by new manager Benito Floro for two friendlies against Mauritania on September 8 and 10.