The Red Devils, who are valued at 1.86 billion dollars, beat NFL team Dallas Cowboys and the New York Yankees top of the list.
Out of the top 50 sports teams in the annual list, all 32 NFL sides were included, while just eight football clubs from around the world made it.
United's advertising revenue has a big impact on their valuation, with the club having an 80 million pounds, four-year deal with shirt sponsor Aon and a 302.9 million pounds, 13-year deal with Nike.
The club also gain their revenue from the club's fanbase, with an estimated 333,000,000 supporters around the world.