Despite failing to lift a single trophy last season, the club can be happy in the knowledge that their name still means something.
United came above Real Madrid and Barcelona on the Forbes list, who placed third and fouth, valued at £3.13billion and £3.11billion respectively.
Bayern Munich were the only non-Premier League football team to make it onto the list, coming in twelth with a vaulation of £2.35billion.
City came 30th (£1.89bilion), while Arsenal (£1.71billion) and Chelsea (£1.58billion) ranked 39th and 46th on the list.
Kurt Badenhausen, a senior editor at Forbes magazine told the 'Daily Mail':
"There has never been a better time to own a top-notch pro sports franchise."
"Blockbuster TV contracts and owner-friendly collective bargaining agreements are fueling record sale prices across major sports leagues."
29 NFL teams made it onto the list, including the Dallas Cowboys, who topped the list with an estimated worth of £3.67billion.
American sports dominated the list, with eight NBA teams and six MLB teams also included in the top 50.