Manchester United fifth in Forbes World list of richest clubs
NFL side, the Dallas Cowboys, are top with $4bn (£3.03bn), the first time a non-association football team has headed the business magazine's list since it began in 2011.
United, who topped the list in 2011 and 2012, are valued at $3.32bn (£2.52bn).
Real Madrid are second with $3.65bn (£2.77bn) and Barcelona third with $3.55bn (£2.69bn).
United - the only English club in the top 20 - saw a 7% increase in their value despite missing out on the Champions League after signing a £750m Adidas kit deal. However, the club have the highest debt load of anyone in the top 25.
Arsenal (23), Manchester City (28), Chelsea (36) and Liverpool (41) are the remaining English clubs to make the list.
The Cowboys, who made a record $270m (£205m) operating profit last season, are one of 27 NFL franchises in the list, while the Formula 1 team Ferrari have dropped out of the top 50 completely.
Forbes' top 10 most valuable teams
1.Dallas Cowboys $4bn (£3.03bn)
2.Real Madrid $3.65bn (£2.77bn)
3.Barcelona $3.55bn (£2.69bn)
4.New York Yankees $3.4bn (£2.58bn)
5.Manchester United $3.32bn (£2.52bn)
6.New England Patriots $3.2bn (£2.43bn)
7.New York Knicks $3bn (£2.27bn)
8.Washington Redskins $2.85bn (£2.16bn)
9.New York Giants $2.8bn (£2.12bn)
10.Los Angeles Lakers $2.7bn (£2.05bn)