Cristiano Ronaldo and Michael Jordan -- two of the wealthiest athletes in the history of the planet -- doubled up for a night out in the French Riviera ... because this is what extremely rich people do.
Ronaldo has been yachting it up with his longtime girlfriend, Georgina Rodriguez, and their kids -- but clearly, they got a babysitter and found some time for a night out with MJ and his wife.
Unclear where they went ... but with Ronaldo reportedly worth somewhere in the ballpark of a billion dollars .