The Cowboys, who have not won a Super Bowl since 1996, jumped five percent in value to $4.2 billion.
The Cowboys, who have not won a Super Bowl since 1996, jumped five percent in value to $4.2 billion (3.68 billion euros) to defend their 2016 position. Last year they unseated Spanish football powerhouse Real Madrid atop the global list.
The 32-team NFL is the world's richest league, with an average operating profit of $91 million and no club turning less than a $26 million profit. A major reason for that was the latest NFL television package bringing annual revenues of $7 billion.
The Cowboys also boast a $1.5 billion team practice facility and headquarters that will become a retail and entertainment complex with hotels, medical center and convention center. An exclusive club offers members the chance to watch Cowboys workouts.
Only three NFL clubs missed the 50-team Forbes richest roll call -- the Cincinnati Bengals, Detroit Lions and Buffalo Bills.
Major League Baseball's New York Yankees ranked second on $3.7 billion, a nine percent boost from last year. They boast $120 million in sponsorships and $130 million in premium seat revenues, tops in the major leagues. In all, eight major league clubs made the Forbes list.
Manchester United ranked a close third on $3.69 billion, hurdling Spanish rivals Barcelona ($3.64 billion) and Real Madrid ($3.58 billion). Barca was up two percent to stand fourth, Real off by the same amount in fifth overall.
In all, seven global football clubs made the list, the others being Bayern Munich, 15th on $2.71 billion; Manchester City, 35th on $2.083 billion; Arsenal, 43rd on $1.93 billion and Chelsea, 46th on $1.845 billion.
The reigning Super Bowl champion New England Patriots were sixth on the list at $3.4 billion, jumping six percent with their run to the NFL title.
Topping NBA clubs in seventh overall were the New York Knicks on $3.3 billion, up 10 percent in value but still weaklings on the court at 31-51. They have not had a playoff berth or winning season since 2013 and have won only one playoff series since 2000.
The NFL's New York Giants were eighth on $3.1 billion with the NFL San Francisco 49ers and NBA Los Angeles Lakers sharing ninth at $3 billion.
In all, there were seven NBA clubs on the list. The reigning champion Golden State Warriors shared 20th with the NFL Houston Texans on $2.6 billion, leaping 37 percent in value.
Last year's NBA champion Cleveland Cavaliers didn't make the list but the NBA-worst Brooklyn Nets at 20-62 shared 47th on $1.8 billion, just ahead of a 50th-place deadlock between the NFL New Orleans Saints and baseball's Los Angeles Angels on $1.75 billion.
The biggest gainer was the NFL Los Angeles Rams, doubling in value after a move from St. Louis to land in 12th overall with a new stadium owned by Rams owner Stan Kroenke set to open in 2020.
Kroenke is also the biggest shareholder in Arsenal, which suffered the list's worst plunge, tumbling 20 spots and off four percent due to a decline in the British pound after Britain voted to leave the European Union.
Two teams from last year fell off the list, the NBA's Houston Rockets and English football side Liverpool. No NHL or auto racing teams made the list.