Born: March 22, 1995 – Montreal, Quebec
Entering 2026:  Years as a Lion: 5th   Years in CFL: 7th Status: National
Career Games: 64   Playoffs: 9   Grey Cup: 0

Acquired:

Mathieu was signed as a free agent by the Lions on February 8, 2022. After signing with the Detroit Lions for the start of 2024, he returned to British Columbia on August 28 following his release from Detroit’s training camp.

Highlights:

2025: The defensive end made more history in his fourth season in black and orange, becoming the first Canadian player in league history to win Most Outstanding Defensive Player twice. He accomplished the feat after leading the league with 15 sacks and becoming the first player in over thirty years to register nine QB takedowns across a three-game span.
Betts’ four forced fumbles were good for a share of the CFL lead with Montreal’s Tyrice Beverette and Toronto’s Isaac Darkangelo, while his 42 defensive tackles fell only two short of his career-high set in the 2023 campaign. Betts enters 2026 sitting sixth on the Lions’ all-time list with 42 sacks, 4.5 behind Nick Hebeler for fifth spot.

2024: Mathieu returned to BC ahead of Touchdown Pacific in Victoria and would record his first sack of the year in that win over Ottawa. In seven regular season games, Betts racked up 13 defensive tackles, two sacks and scored his first career touchdown on an interception return during a win over Calgary on October 6.

2023: It was a record-setting campaign for Betts as his 18 quarterback sacks set a new single-season Canadian mark previously held by Lion legend Brent Johnson and Jamaal Westerman. Betts was the first Lion to lead the CFL in sacks since Keron Williams in 2012 while his 42 defensive tackles set a new career-high. He would be recognized for his stellar season with the CFL Most Outstanding Player Award while collecting West Division and CFL All-Star nods for the first time in his career.

2022: Mathieu emerged as one of the Lions’ most impactful additions in 2022, suiting up in all 18 regular season games for the first time in his career while racking up career-highs in defensive tackles (29) and sacks (seven). Betts went on to record seven more defensive tackles and a pair of sacks in two playoff games.

2021: Mathieu suited up for 13 games in a shortened season and registered 12 defensive tackles for the Edmonton Elks.

2019: Mathieu signed with the Chicago Bears as an undrafted free agent on April 27, 2019. He was also selected third overall in the 2019 CFL Draft by Edmonton on May 2, 2019. Following the roster cut by the Bears on August 31, 2019, Mathieu officially joined Edmonton for the remainder of the 2019 season where he registered one defensive stop, two sacks and one forced fumble.

Kudos:
All-CFL: 2023, 2025
West Division All-CFL: 2023, 2025
CFL Most Outstanding Defensive Player: 2023, 2025

College:

Mathieu played for the Laval Rouge et Or from 2015-2018. The defensive line dominated the line of scrimmage. He led U Sports with 12 sacks as a rookie and collected individual awards like the Peter Gorman Trophy, the Rookie of the Year for football, and J.P. Metras Trophy, U Sports most outstanding defensive lineman three years in a row (2016, 17, 18). Mathieu also helped the Rouge et Or hoist the Vanier Cup in 2016 and 2018.