Panathinaikos
That is debatable. Michigan has had the most fans in a stadium in a game, and there are fans growing everyday.
Persepolis is the greatest pro football team.
Manchester united
LIVERPOOL
Most likely the pittsburgh steelers
Brazil
Dallas Cowboys
Michigan
PSG by a long distance
Celtic Fc has the most fans followed by Rangers FC! mon the hoops:D
The NFL team with the most fans is the Dallas Cowboys. The Green Bay Packers have the second most fans, followed by the Denver Broncos, and the NY Giants.