Chicago bears From 1933, when the first NFL championship game was played, to 2008, when Super Bowl XLII was played, the team that has lost the most NFL championship games is the New York Giants who have lost 11 NFL championship games (pre Super Bowl) and 1 Super Bowl for a total of 12.
I think weber state wildcats has lost the most nataiol games
Northwestern's Wildcats have lost the most Division 1 games: 596
The Pittsburgh Steelers have played in 15 championship games. The most in NFL history.
45 had won the most championship football games
The Pittsburgh Steelers have played in 15 AFC championship games. That is the most in NFL history.