Elon Musk and President Trump look like they are back on good terms ... because they're sitting shoulder to shoulder at the Charlie Kirk memorial service.

Elon and Trump were spotted Sunday in a luxury suite at the Kirk memorial at State Farm Stadium in Glendale, Arizona.

The Tesla honcho had a bitter falling out with POTUS a few months ago ... but now it looks like they've patched things up ... and cameras even caught them chatting and shaking hands.

Remember ... Elon and Trump's falling out started when Elon publicly ripped Trump's Big Beautiful Bill, blasting it as wasteful and damaging to the economy. Trump responded by threatening federal action against Elon's companies and launching personal attacks. Elon then claimed Trump was on the Jeffrey Epstein client list.

Elon eventually walked things back and said he regretting taking things too far ... and now it looks like he's out of the President's doghouse.