Rich Stubler began his CFL coaching career in 1983 when he joined the Hamilton Tiger-Cats, helping lead the team to a Grey Cup in 1986 as linebackers coach. In 1990, Stubler was the defensive coordinator for the Toronto Argonauts. He joined the Edmonton Eskimos’ coaching staff in 1991, winning his second league championship in 1993. Stubler's "Edge" defense was noteworthy for lining up defensive tackles and ends 1-2 yards off the line of scrimmage to offer defensive linemen better vision and tackling angles; it allowed the fewest points in their division in the 1993 season (12-3 record in the CFL West), the second fewest in the 1994 season (13-5 in the CFL West), and the fewest in the 1995 season (13-5 in the CFL North).
Following the 1995 season, Stubler was hired as Defensive Coordinator by University of Oregon Head Coach Mike Bellotti. Bellotti, with a team fresh off appearances in the 1994 Rose Bowl (with Nick Allioti, Defensive Coordinator) and the 1995 Cotton Bowl (with Charlie Waters, Defensive Coordinator), was intrigued by Stubler's defensive innovation. Whether due to personnel, strategy, or the differences between CFL and NCAA football, Stubler's Oregon defenses could not duplicate Edmonton's success: Oregon finished the 1996 Pac-10 season with the 9th rated defense in the conference, a 6-5 (3-5 Pac-10) record, and did not go to a bowl; Oregon finished the 1997 Pac-10 season with the 10th rated defense (440.5 ypg, 30.6 ppg) in the conference, a 7-5 (3-5 Pac-10) record, and played in the Las Vegas Bowl.
Stubler resigned from Oregon prior to the Las Vegas Bowl in December, 1997 to resume his career in the CFL, rejoining the Edmonton Eskimos from 1998 to 1999 before moving on to help the BC Lions capture the Grey Cup in 2000.
Stubler coached in the Arena Football League as the defensive coordinator for the expansion Detroit Fury from 2001 to 2002. Upon the conclusion of both AFL seasons, Stubler rejoined the Toronto Argonauts late into their seasons as a defensive consultant.
In 2003 Stubler joined the Argonauts full-time as their defensive coordinator. In 2004, the Argonauts defeated the BC Lions 27–19 in the 92nd Grey Cup to give Stubler his fourth championship. On December 6, 2007, he was announced to replace the outgoing Pinball Clemons as head coach of the Argonauts for 2008.
After a 4–6 start to the 2008 season, Stubler was fired as head coach of the Toronto Argonauts on September 9, 2008, and replaced with former Argonauts' head coach Don Matthews.
For the 2009 off-season and the 2009 season, Stubler was hired by Cedaredge High School, the small public high school of Cedaredge, Colorado, as head coach. Stubler explained his choice for the no-name football team with needing a break. The team, which had shown weak performances in previous years, finished the season with Stubler with 2 wins out of 10 games (no draws).