The UFC has no shortage of star power at its events -- in and out of the Octagon -- so, who's gotten the loudest pop from the crowd?!

Dana White has an answer.

"When you think about fighter walkouts, whenever a fighter walks out to the [Octagon] — I mean, the two biggest that actually shake the arena are President Trump and Conor McGregor, two of the biggest fight walkouts ever," the UFC boss told Babcock on the TMZ Sports TV show (airs nightly on FS1).

Of course, UFC 309 is going down Saturday night at Madison Square Garden in NYC -- the first PPV event since Trump defeated Kamala Harris by a landslide last Tuesday -- so we asked Dana whether DJT would be in the house.

"I think that anything is possible. He's a big fan. Who knows? He could pop in," White told us with a smile on his face.

Dana and Donald go way back.

In the early days of White's UFC ownership, when states (like New York -- which now loves the UFC) and venues alike refused to host MMA fights, Trump offered up his Atlantic City casinos ... at a time when the promotion was struggling to just get by.

When DJT decided to run for president leading up to the 2016 election, DW was right there by Trump's side, speaking out early and often on behalf of his close friend.

In other words, the men share an incredibly strong bond ... so don't be shocked at all if Trump's first high-profile public appearance comes at UFC 309.

Check out the full interview ... DW and MB talk about Jon Jones vs. Stipe Miocic (biggest heavyweight fight ever?), Bones' future (could this be Jon's last fight? Is Jones ducking Tom Aspinall?), and much more ... including why White should probably just write Michael Chandler and Charles Oliveira a $50K check right now.