The 1891 Yale Bulldogs football team represented Yale University in the 1891 college football season. The team finished with a 13–0 record and a 488-0 season score. It was retroactively named as the national champion by the Billingsley Report, Helms Athletic Foundation, Houlgate System, National Championship Foundation, and Parke H. Davis. Yale's 1891 season was part of a 37-game winning streak that began with the final game of the 1890 season and stopped at the end of the 1893 season.

The 1891 Western University of Pennsylvania football team was an American football team that represented the Western University of Pennsylvania as an independent during the 1891 college football season.