Drake didn’t only kill Meek Mill onstage at OVO Fest  … he burned him backstage too — sharing a HUGE laugh with Kanye West and Will Smith.

Rumor is … the superstars went all LMFAO over a meme Drake used to mock his rival. Check out the video … it’s hard to make out what’s on Will’s iPhone screen, but THEY think it’s hysterical.

What is 100% clear — Will looks really tight with Toronto’s favorite son! Damn, Meek.

So much for, “In West Philadelphia born and raised …”