The 2008 Toronto Argonauts season was the 51st season for the team in the Canadian Football League and 136th season overall. The Argonauts attempted to win their 16th Grey Cup, but they failed to make the playoffs ending the season on a nine-game losing streak.
 In the 2008 CFL Draft, 48 players were chosen from among 752 eligible players from Canadian universities across the country, as well as Canadian players playing in the NCAA. The first two rounds were broadcast on TSN.ca with host Rod Black.
 
 As of June 10, 2008
 Running backs
 Receivers
 Defensive linemen
 Defensive backs
 Special teams
 Suspended list
 Practice Roster
 Italics indicates Import player
Roster updated 2008-06-10
Depth Chart • Transactions
69 Active, 3 Inactive
 Running backs
 Receivers
 Defensive linemen
 Defensive backs
 Special teams
 Italics indicates Import player
Roster updated 2008-10-31
Depth Chart • Transactions
55 Active, 4 PR
 
 
 Toronto started the season off well, winning against the Blue Bombers 23–16, but after that they compiled a 2–5 record the next 7 games. After the Bye week, everything went downhill, they won only one game and lost 9 start to finish the season 4–14 and missed the playoffs.
 A raucous Labour Day crowd of 25,911 at Ivor Wynne Stadium witnessed a game that ended with a 34–31 Argo victory, the team's first win against the Hamilton Tiger-Cats of the season. Argo head coach Rich Stubler's job was rumoured to be on the line. Argos receiver Arland Bruce III found time for a little theatrics, celebrating an 11-yard TD catch by donning a Spider-Man mask produced from his pants. Several days later, the Canadian Football League fined the Argonauts receiver an undisclosed amount for his touchdown celebration. Game officials had handed Bruce an objectionable conduct penalty after the incident. Bruce went on to have his best game of the season, catching 10 passes for a game-high 149 yards.
 On September 9, Stubler was released as head coach of the Argonauts after posting a 4–6 record. There was the belief he could not get along with those he worked with. The Argos hired Don Matthews, the head coach with the most wins in CFL history and head coach during Toronto's back-to-back Grey Cup victories in 1996 and 1997, to return to the club as head coach for the third time in his coaching career.
 During the team's next game on September 12 at Rogers Centre, Winnipeg Blue Bombers slotback Milt Stegall became the most prolific receiver in the history of the CFL. The slotback caught a 92-yard pass at 9:02 in the second quarter to raise his career total to 14,983, breaking the mark of 14,891 yards previously held by former Stampeders receiver Allen Pitts. Stegall took a pass from Kevin Glenn and scored a touchdown, his second of the game. It put the Bombers ahead 28–3.
 On October 31, Matthews resigned from the Argonauts a day after the conclusion of the Argonauts 2008 regular season, which saw the Argos fail to win a game in the eight games under his leadership and finishing out of the playoffs for the first time since the 2001 CFL season.
 
 
 
 The Argos finished third in the East Division with a record of 4 wins and 14 losses. The Edmonton Eskimos, who finished fourth in the West, had a better record of 10 and 8, and under the cross-over rule eliminated Toronto from the playoffs and play the Winnipeg Blue Bombers in the East semi-final.