Many of the top 10 in the annual top 50 are American football NFL franchises.
Manchester United arrive in Durban late today ahead of a midweek friendly with AmaZulu and another against Ajax Cape Town this weekend.
The 19-time champions of England, who are preparing to be listed on the New York Stock Exchange, were valued at $2.23 billion [£1.42 billion], up from $1.86 billion [£1.19m] last year and 19 per cent above second-place Los Blancos at $1.88 billion [£1.2 billion].
The top 50 list, which is collectively worth $53 billion [£33.9 billion], included seven football teams, with Arsenal falling three places to 10th and Barcelona rising 18 spots to eighth.
United, who are owned by the Glazer family which also own the NFL's Tampa Bay Buccaneers, can thanks the many lucrative global sponsorship deals in their arsenal for their top ranking. Insurer Aon are currently paying £19.8 million a year until 2014 to have their name on the team’s shirts.
DHL Express also recently signed a four-year deal with the club worth a reported £40 million to sponsor United's training shirts, in a first for a practice kit sponsorship deal for football in the UK, while sports brand Nike manages the team's merchandise sales in and agreement worth approximately £25 million annually.
The rest of the top 10 is comprised of American sports franchises, with the Dallas Cowboys and New York Yankees tied for third place.
Bayern Munich were placed just outside of the top 10 at 11th, while AC Milan featured 27th on the list, with Chelsea the final football representative at number 45.