The 1940 NFL season was the 21st regular season of the National Football League. The season ended when the Chicago Bears defeated the Washington Redskins in the NFL Championship Game, 73–0. This game still stands as the most one-sided victory in NFL history. The Pittsburgh Pirates were renamed the Pittsburgh Steelers before the 1940 season.
Major rule changes 
- The penalty for a forward pass not from scrimmage is 5 yards.
- Penalties for fouls that occur prior to a pass or kick from behind the line of scrimmage are enforced from the previous spot. However, penalties for fouls during a free ball or when the offensive team fouls behind their line are enforced from the spot of the foul.
- Fouls enforced in the field of play cannot penalize the ball more than half the distance to the offender's goal line.
- If the offensive team commits pass interference in their opponent's end zone, the defense has the choice of 15 yards from the previous spot and a loss of down, or a touchback.
Final standings 
W = Wins, L = Losses, T = Ties, PCT= Winning Percentage, PF= Points For, PA = Points Against
Note: The NFL did not officially count tie games in the standings until 1972
NFL Championship Game 
Chi. Bears 73, Washington 0, at Griffith Stadium, Washington, D.C., December 8, 1940