Legend respects legend.

Christie Brinkley just dropped some SERIOUS praise on Serena Williams -- saying her nude, pregnant Vanity Fair cover is bomb as hell ... and it would be an "honor" to work with her! 

The modeling icon turned business mogul couldn't stop gushing over the photo -- saying on a scale of 1 to 10, Serena's pic was an 11, "Off the scale! She's over-the-top amazing!" 

Wouldn't be a terrible idea for these two to hang out -- Brinkley used her modeling cash to fund a real estate empire and reportedly built a fortune around $100 MILLION! 

#BossFemalesWinning