The A-lister threw a massive bash Friday to celebrate his birthday at a private mansion in Beverly Hills, where a lot of famous faces were seen coming and going throughout the night. Truly, it was a classic who's-who of Hollywood ... something only a select few can pull off.

Among the high-profile guests ... LeBron James, Bradley Cooper, Sir Mick Jagger, Tobey Maguire, Adrien Brody, Jamie Foxx, Rami Malek, Casey Affleck, Wesley Snipes, Stella Maxwell, Nicky Hilton, Sommer Ray, Jennifer Meyer, Caylee Cowan and many, many more.

This shindig was pretty private -- Leo reportedly had folks throw their phones into secure bags before entering, so you might not be seeing many photos posted on anyone's Story.

Definitely on par with the type of pomp and circumstance we'd expect from LDC -- after all, the guy played the Great Gatsby ... so he knows how to throw a good rager, it seems.