Prior to 1932, the NFL had undefeated seasons (with ties). Season 8 / 3 of the 1920 Akron Pros 1 game canceled in the 1922 Canton Bulldogs season (10-2), 11-1 in the 1923 Canton Bulldogs season, and 12 in the 1929 Green Bay Packers season.
In 1932, the Chicago Bears finished with a 10-0 record but lost their final game against St. Louis Rams. The next year, the Detroit Lions finished with an identical 10-0 record but did not play any games due to World War II. In 1950, the Cleveland Browns finished with a 9-0 record but lost their only game against Washington Redskins. In 1954, the Brownies finished with an 8-0-2 record but lost their last two games against Philadelphia Eagles and New York Giants.
Since then, there have been many more perfect seasons - some winning the Super Bowl others not. The 1972 Miami Dolphins finished with a 10-0 record but lost their only game against Pittsburgh Steelers. The 1978 Dallas Cowboys finished with a 10-0 record but lost their last game against Philadelphia Eagles. In 1983, the San Francisco 49ers finished with a 10-0 record but lost their last game against Tampa Bay Buccaneers. In 1990, the Buffalo Bills finished with a 10-0 record but lost their last game against New York Jets. In 1992, the Dallas Texans finished with a 10-0 record but lost their only game against Los Angeles Raiders.
Several unbeaten and untied teams competed in the 1929 collegiate football season. Purdue, Tulane, Notre Dame, and Pittsburgh all ended the regular season undefeated. However, only Purdue played a non-conference game against Indiana that year and lost 7-0. The other three teams were all members of the Midwestern Conference, and they met in two conference games and one post-season tournament. In those four games, Purdue was victorious twice by a margin of 10 points or more.
Purdue finished its season with a 1-1 record and was awarded an undisputed national championship by several publications. They were ranked No. 1 by both the Dickinson System and the Poling Scoreboard Report. However, neither team has ever been officially recognized by the NCAA as a champion.
In addition to Purdue's title, several other schools claimed to be undefeated and/or untied. However, all of these teams lost at least one game during the season and some lost multiple games. Georgia claimed to be undefeated and untied after winning its first six games but lost to Vanderbilt in November. Miami (now Miami University) also claimed to be undefeated and untied after opening the season with six wins but lost for the second consecutive year when Syracuse defeated them 21-7 on New Year's Day 1931.
Aside from the 1972 Miami Dolphins, three NFL teams have gone undefeated and unbeaten in regular season: the 1934 Chicago Bears, the 1942 Chicago Bears, and the 2007 New England Patriots. The 2014 Denver Broncos were one game over.500 when they finished the season undefeated.
The last team to go into a season undefeated was the 2002 Tampa Bay Buccaneers. That year, they went 12-0 and won the Super Bowl. The only team to beat them during the season were the 2002 Jacksonville Jaguars. The two teams met twice that year, with the Jaguars winning both games. The last time an NFL team went 12-0 was the 1972 Miami Dolphins. They started out the season 13-0 before losing their final game of the season against the Buffalo Bills.
In college football, only Oklahoma has done it since the inception of the NCAA Division I Football Championship Subdivision (formerly known as Division I-A). The Sooners went 14-0 in 1999 and were ranked No. 1 throughout most of the season. However, they lost at home to Texas Christian University 34-28 with just under 10 minutes left in the game. Texas Christian would go on to lose their next game to Nebraska 23-20 in overtime!
No team has gone 16-0 since the Oklahoma Sooners did so in 1999.
Green Bay Packers, the 1929 NFL champions
Say it out loud: BEARS ARE DEFEATED AND CAPTURED BY PAUSEBAYS 9th Title (1929) Chicago, Illinois – The Green Bay Packers claimed the National Professional Football League championship here Sunday afternoon, defeating the once-dominant Chicago Bears, 25 to 0, in the Packers' last league game of the season.
1940 in sports refers to the events of the year in the world of sports. In the NFL championship game, the Chicago Bears beat the Washington Redskins 73-0. This game still retains the record for the highest scoring game and the largest victory in National Football League history.
The record was first set by the Detroit Lions who played a match against the Cleveland Rams on December 29, 1940. The game ended in a 7-7 tie after both teams scored twice each. The next day, the two clubs again met on Christmas Day at Cleveland Stadium with the same result. The match was finally decided in favor of the Lions by default as the Rams failed to show up for the final whistle. Dave Martin scored six goals on offense and defensive end Joe Schmidt added five of his own.
This is one of only two occasions when a professional football team has achieved a perfect season. The other one occurred in 1972 when the Miami Dolphins defeated the Buffalo Bills 26-0. Both games were held on December 30, 1940.
In addition to these two games, several other matches have been tied in league history. A match between the Chicago Bears and Los Angeles Rams was scheduled for October 20, 2016, but it was canceled due to weather conditions that day. If this game had taken place, it would have been the most-watched NFL game ever with an estimated audience of more than 60 million people.