United were valued at $3.69 billion (£2.86bn), an 11 percent jump compared to a year ago.
According to the U.S. business magazine, United have generated revenues of 593 million pounds during the 2015-16 season despite the club's failure to finish in the top four.
"Manchester United's return to the top spot is a testament to their powerful brand and marketing acumen", said Mike Ozanian, Assistant Managing Editor at Forbes Media. Barcelona come in second at $3.64 billion, followed by Liga Santander and Champions League winners Real Madrid at $3.58 billion. Manchester United is also by far the most profitable soccer team in the world, posting operating income of $288 million, $107 million more than runner-up Real Madrid.
I don't want De Gea to go anywhere and neither does any other United fan and if we can keep him as well as sign four top players then we'll be in such a strong position to compete on all fronts next season.
Possible London attacker with canisters on body shown lying on ground
Two other incidents also were reported, stabbings at nearby Borough Market and another incident in the Vauxhall area of the city. Police have said a third incident is developing in the Vauxhall area, which is about 2 miles southwest of the London Bridge area.
The top five was completed by Bundesliga giants Bayern Munich ($2.71 billion) and English Premier League side Manchester City ($2.08 billion). The big Italian club got the qualification to the Europa League after an odd year, because they started very well but struggled at the end of the season.
The financial might of English football is reflected in the fact that six of the top 10 most valuable clubs hail from the Premier League.
German champions Bayern Munich ($2.71bn/£2.10bn) were ranked fourth while Serie A champions Juventus ($1.26bn/£980m) - who lost the 2017 Champions League final to Real Madrid - were ninth.
With a new 61,000-seater stadium under construction, Tottenham Hotspur ($1.06 billion) rounds off the top 10.