Below is a list of professional football championship games from the three leagues that played the most important roles in professional football: While the AFPA started play in 1920, for their first thirteen years of existence, the league and its successor, the NFL, did not have a "championship game". League "champions" were determined by won-loss record, but the schedules and rules were so ill-defined that conflicts, over who the actual champions were in some years, exist to this day. Some teams played more games than others; some played against college or semi-pro teams; some played after the season was over, some stopped play before a season was over. For example, in 1921, the Buffalo All-Americans disputed the Chicago Staleys' title, and in 1925, the Pottsville Maroons claimed the championship was theirs, not the Chicago Cardinals'.

George Preston Marshall, whose discriminatory signing practices would spread throughout the NFL making it a "no blacks" league, nonetheless is credited with significant innovations. In 1933, Marshall convinced the NFL to play a championship game between two division winners. Thus, 1933 was the year of the first professional football championship game.

"World Champions"

Though many leagues' champions have proclaimed themselves "world champions", for professional football the claim is invalid, except for four years. From 1933 through 1945, 1950 through 1959, and 1970 through the present, the NFL has acclaimed its champions as "world champions". However, since there was essentially ONLY ONE LEAGUE during those years, those claims are spurious. From 1946 through 1949, both the NFL and the AAFC said their champions were "world champions", as did both the NFL and the American Football League from 1960 through 1965. Since the NFL never deigned to have its champions play the other league's champions, those claims are likewise hollow.

Thus, the only World Championships of Professional Football were decided for the four seasons of 1966 through 1969, when the champions of the American Football League played the champions of the NFL to determine an overall champion.

Professional Football Championship Games

(Years indicate the SEASON, not necessarily the year in which the game was played.)