Dickenson was eligible for the
1996 NFL draft, but went undrafted.
Calgary Stampeders (first stint) Dickenson was on the negotiation list of the
Toronto Argonauts. His rights were traded to the
Calgary Stampeders for wide receiver
Tyrone Williams. Dickenson signed with Calgary for the
1996 season. That year, he was a reserve quarterback and did not dress for any games. In
1997, Dickenson got his first CFL start when Calgary's starting quarterback,
Jeff Garcia, was unable to play October 18 when Calgary played in Toronto. Calgary would go on to lose 48–17. Dickenson also got significant playing time when Garcia got injured in the first quarter of the West Semi-Final against Saskatchewan. In a losing cause, Dickenson went 25 of 36 for 292 yards and 2 touchdowns and 0 interceptions passing, and had a 14-yard rushing touchdown. In
1998, Dickenson made his second CFL start when Calgary played in Winnipeg on July 24 because Garcia was sidelined with a knee injury. Calgary won 44–25. The Stampeders would go on to win the
Grey Cup 26–24 over
Hamilton that year, and Dickenson was the holder on the winning field goal. In
1999, Garcia joined the
San Francisco 49ers, and Dickenson became Calgary's starting quarterback. Despite suffering some injuries during the season, Dickenson was able to guide Calgary back to the
Grey Cup game. This time, Calgary would lose to Hamilton 32–21. His best year with the Stampeders was
2000. Dickenson led the CFL in passing efficiency (114.1) and completion percentage (64.3%). During the 2000 season, Dickenson earned Player of the Week honors once, was named a
CFL All-Star, and won the
CFL's Most Outstanding Player Award. The Stampeders finished first place in the West Division in a year that Calgary was hosting the Grey Cup, and hosted BC in the West Final. In the West Final, Dickenson struggled, going 4 of 11 for 53 yards and 2 interceptions and 1 touchdown passing. On the touchdown pass, Dickenson suffered a knee injury that forced him from the game. Calgary would go on to lose 37–23.
National Football League After generating interest from the
NFL following his outstanding
2000 CFL season, Dickenson spent two seasons (
2001-
2002) in the National Football League. He spent the entire 2001 season as the third string QB for the
San Diego Chargers, but was released by San Diego at the end of training camp in 2002 after a disappointing preseason in which he did not get to play in a game. He was then signed by the
Seattle Seahawks and served as the third QB for two games before being released on September 24. In October, he signed with the
Miami Dolphins following an injury to
Jay Fiedler, and served as their third QB until December 3. He finished the season as the third QB for the Detroit Lions for their final two games after
Joey Harrington was diagnosed with an irregular heartbeat.
BC Lions Dickenson signed as a free agent with the
BC Lions in
2003, reuniting him with his head coach in Calgary,
Wally Buono. During the 2003 season, in which he led the Lions into the playoffs with an 11–7, 4th-place finish in the
CFL West Division, Dickenson's 36 touchdown passes and were the second-highest single season marks in Lions' history behind
Doug Flutie in 1991. Dickenson was named Offensive Player of the Month for August 2003, was the CFL Player of the Week in Week 5, and was awarded the
Jeff Nicklin Memorial Trophy as the CFL West Division's Most Outstanding Player. Dickenson was unable to play in the team's playoff game in Toronto due to injury. BC lost 28–7. In
2004, Dickenson began the season as the Lions' starting quarterback, but gave way to backup
Casey Printers after suffering a knee injury. Printers put on a dominating performance for the rest of the season, and won the CFL's Most Outstanding Player award. In the West Division Final against the
Saskatchewan Roughriders, Printers was forced to leave the game with a shoulder injury in the fourth quarter, with the score tied 14-14. Dickenson, having recovered from knee surgery and shared quarterbacking duties with Printers late in the season, played the rest of the game and threw a touchdown pass in the Lions' 27–25 overtime victory. Dickenson would start and play the entire
Grey Cup game against the
Toronto Argonauts, which the Lions lost by a score of 27–19. Dickenson began the
2005 season embroiled in a quarterback controversy with Printers. Dickenson emerged as the starter, and was instrumental in leading the
Lions to an 11–0 start (where he played in 9 of the 11 games), en route to a league-best 12–6 season finish. Dickenson set an all-time CFL record with a passing efficiency mark of 118.8. He fell just short of the attempts required to set a further mark with a 74.0% completion rate, due to 4 games missed because of a concussion. Dickenson was named CFL Player of the Month for both July and September, and was Player of the Week twice. BC hosted Edmonton in the West Final, but lost 28–23, which meant BC would not be playing in the Grey Cup the following week. In
2006, BC's quarterback controversy ended when Printers joined the
Kansas City Chiefs. Dickenson threw for and 22 touchdowns while only playing 13 games. He led the Lions to the franchise's
5th Grey Cup title on November 19, 2006, with a 25–14 win over the
Montreal Alouettes. Dickenson was named the
Grey Cup Most Valuable Player. Dickenson's
2007 season was interrupted early by a serious concussion received on a hit from Saskatchewan's
Fred Perry.
Jarious Jackson eventually led the team to another first-place finish and franchise record 14 wins, but the Lions were defeated in the playoffs with a recovered Dickenson being called on to relieve Jackson. Dickenson was released from the BC Lions on November 26, 2007, after five seasons with the team.
Calgary Stampeders (second stint) On January 31,
2008, Dickenson signed as a free agent with the Calgary Stampeders. He returned to the city where he lived with his family, and to the team where he began his professional career. He was reunited with his offensive coordinator from his first season in Calgary,
John Hufnagel. Hufnagel had recently been hired as Calgary's General Manager and Head Coach. Dickenson's brother,
Craig, was on the staff as special-teams co-ordinator. Dickenson's only playing time that season came in the
Labour Day Classic filling in for an injured
Henry Burris. However, his return was short lived, as post concussion symptoms returned, thus ending his long storied career in professional football. Dickenson remained with the Stampeders for the rest of the season. Calgary went on to win the
Grey Cup 22–14 over Montreal. Dickenson retired as a player on February 4, 2009. In 2015, Dickenson was inducted into the
Canadian Football Hall of Fame. ==Playing statistics==