Soccer teams Manchester United ($4.12 billion), Real Madrid ($4.09 billion) and Barcelona ($4.06 billion) occupied the next three spots.
The Dallas Cowboys have been ranked the world's most valuable sports team for a third consecutive year, an annual list published by Forbes showed on Wednesday, with the National Football League accounting for more than half of the top 50.
The NFL's Cowboys were valued at $4.8 billion, a 14 percent jump compared to last year, Forbes said in a statement.
Soccer teams Manchester United ($4.12 billion), Real Madrid ($4.09 billion) and Barcelona ($4.06 billion) occupied the next three spots.
Major League Baseball's New York Yankees, who were second on the list last year, rounded out the top five with a value of $4 billion, up 8 percent from a year ago.
The average value of the 50 teams on the list is $2.74 billion, the highest to date, up from last year when the average value was $2.5 billion
"There has never been a better time to own a top-notch pro sports franchise," said Kurt Badenhausen, a senior editor at Forbes.
"Blockbuster TV contracts and owner-friendly collective bargaining agreements are fuelling record sale prices across major sports leagues."
Teams from the NFL, whose lucrative broadcast contracts dwarf those of other leagues, took up 29 of the top 50 spots.
The National Basketball Association had eight teams on the list, led by the Los Angeles Lakers ($3.3 billion) in eighth place, followed by European soccer and MLB, who had seven and six teams.
No ice hockey, Formula One or Nascar teams made the cut.
