UFC's Mackenzie Dern Shows Christmas Time Is Bikini Time In Brazil

Here's UFC star Mackenzie Dern showing her holiday spirit ... rocking a tiny bikini in Brazil, where it's 80 degrees and sunny in the middle of December!

The 26-year-old jiu-jitsu champion is coming off an impressive fight against Amanda Ribas -- who she fought in October, just 4 months after Dern gave birth to her daughter, Moa.

Dern lost the scrap, but the fact she was able to get back into fighting shape in just 124 days -- and fought Ribas all the way to a decision after three 5-minute rounds is pretty damn amazing!

Now, Dern is back home in Brazil where she's getting in some quality beach time with her family -- including longtime boyfriend Wesley Santos, a pro surfer.

No word on when Dern will return to the Octagon and fight again -- but she's been back in the gym and we're told she's planning on taking a fight in early 2020.