NFL side the Dallas Cowboys, valued at $5bn (£4bn), remain top, with Major League Baseball’s the New York Yankees second on the list at $4.6bn (£3.7bn).
Real Madrid are third, with fellow Spanish side Barcelona in fourth.
Manchester City (25), Chelsea (32), Arsenal (42), and Liverpool (45) are the other English clubs in the top 50.
The Dallas Cowboys have been number one for the past four years having usurped Real Madrid in 2016.
“The values of teams in major sports leagues are booming thanks to sky-high TV deals, both local and national,” said Kurt Badenhausen, senior editor at Forbes Media.
“And with revenue growing faster than player salaries, franchises are more profitable than they have ever been.”
NFL teams made up 26 – down from 29 a year ago – of the top 50 teams on the list.
The NBA had nine teams on the list, while there were eight from European football and seven from MLB.