Bellefeuille was hired by the Ottawa Gee-Gees as their assistant head-coach in 1995. He spent the next three seasons at the same position before being promoted to head coach in 1998. In 1999, he was named OQIFC Coach of the Year and then, in 2000, he led the Gee-Gees to a Vanier Cup victory.
After the win in the Vanier Cup, Bellefeuille was hired by the Saskatchewan Roughriders as an assistant. In 2003, he was named the offensive coordinator. In three seasons, he helped the Roughriders running backs total 7,000 rushing yards.
After leaving Saskatchewan, Bellefeuille joined the Montreal Alouettes in 2006 as their running backs and wide receivers coach. In 2007, he was promoted to Offensive Coordinator and running backs coach. In his 1st season in Montreal, he helped Robert Edwards lead the CFL in touchdowns with 17. Bellefeuille also helped the Alouettes be the only team with two 1,000 yard receivers in Kerry Watkins and Ben Cahoon.
In 2008, Bellefeuille was hired by the Hamilton Tiger-Cats to be their offensive coordinator and Quarterbacks coach. In September 2008, following Charlie Taaffe's firing, he was named the interim head coach. On October 27, he was officially named Taaffe's replacement. His record as the Ti-Cats interim coach was 1-7-0. On January 15, 2009, Bellefeuille completed his staff shake-up by hiring Greg Marshall as his defensive coordinator and Mike Gibson as his offensive coordinator. Before the Tiger-Cats final 2009 preseason game against the Toronto Argonauts, Bellefeuille said that, "The only thing we know for certain as a coaching staff and as an organization is that Nick Setta will be our kicker." In 3 full seasons as the head coach of the Ti-Cats, Marcel Bellefeuille transitioned the team into a mediocre football club. From 2003 to 2007 the Hamilton Tiger-Cats had a record of 22-60-1. Under Bellefeuille (from 2008 to 2011) they were 26-28, making the playoffs every season and going to the East Final in 2011. The fan-base and ownership became weary of the mediocrity of the team under Bellefeuille and relieved of him of his duties following the 2011 Season.
Bellefeuille's position with the Tiger-Cats ended following the 2011 season. Prior to the 2012 UFL season, Bellefeuille was announced as Offensive Coordinator and wide receivers coach for the United Football League's Omaha Nighthawks. Like Bellefeuille, Omaha head coach Bart Andrus is also a former CFL head coach, having coached the Toronto Argonauts in 2009.
On August 12, 2013, Bellefeuille signed on with the Winnipeg Blue Bombers of the CFL as a member of the team's offensive coaching staff. Six days later, he was promoted to offensive coordinator following the dismissal of Gary Crowton.
Bellefeuille was born in Ottawa, attended Ridgemont High School, and played both running back and defensive back with the Ottawa Gee-Gees. He now lives with his wife Julie and their four children (2 sons:Mathias Bellefeuille and 2 daughters) Winnipeg, Manitoba.