|Duration||September 30 – December 16, 1923|
The 1923 NFL season was the fourth regular season of the National Football League. For the first time, all of the clubs that were considered to be part of the NFL fielded teams. The new teams that entered the league were the Duluth Kelleys, the St. Louis All Stars (which only lasted one season), and a new Cleveland Indians team, while the Evansville Crimson Giants dropped out of the league and folded. The Canton Bulldogs repeated as NFL Champions after ending the season with an 11–0–1 record.
Six days after the December 9 end of the NFL season, league champion Canton accepted a challenge to play against the Frankford Yellow Jackets of Philadelphia, who were not an NFL team but who had billed themselves as "champions of the East" with a 9-1-2 record against teams in the "Anthracite League" and against four other NFL teams. Canton won the game in Philadelphia in the final two minutes of play on a field goal from future Hall of Famer Pete Henry.
Twenty teams competed in the NFL during the 1923 season.
|First season in NFL *||Team folded this season ^||Last season before hiatus, rejoined league later §|
|First season in NFL, and then folded after this season *^|
|Akron Pros||Dutch Hendrian (5 games) and Wayne Brenkert (2 games)||Akron League Park|
|Buffalo All-Americans||Tommy Hughitt||Canisius Field and Buffalo Baseball Park|
|Canton Bulldogs §||Guy Chamberlin||League Field|
|Chicago Bears||George Halas||Cubs Park|
|Chicago Cardinals||Arnie Horween||Comiskey Park|
|Cleveland Indians *||Cap Edwards||Dunn Field|
|Columbus Tigers||Gus Tebell (3 games) and Gaylord Stinchcomb (7 games)||Neil Park|
|Dayton Triangles||Carl Storck||Triangle Park|
|Duluth Kelleys *||Joey Sternaman||Duluth Athletic Park|
|Green Bay Packers||Curly Lambeau||Bellevue Park|
|Hammond Pros||Wally Hess||Traveling team|
|Louisville Brecks ^||Jim Kendrick||Parkway Field|
|Milwaukee Badgers||Jimmy Conzelman||Milwaukee Athletic Park|
|Minneapolis Marines||Harry Mehre||Nicollet Park|
|Oorang Indians ^||Jim Thorpe||Traveling team|
|Racine Legion||Babe Ruetz||Horlick Field|
|Rochester Jeffersons||Leo Lyons||Edgerton Park|
|Rock Island Independents||Herb Sies||Douglas Park|
|St. Louis All-Stars *^||Ollie Kraehe||Sportsman's Park|
|Toledo Maroons ^||Guil Falcon||Swayne Field|
|Green Bay Packers||7||2||1||.778||85||34||W5|
|Rock Island Independents||2||3||3||.400||84||62||L1|
|St. Louis All-Stars||1||4||2||.200||25||74||L1|
Note: Tie games were not officially counted in the standings until 1972.