Jake Paul's ready to cut loose after his big win over Mike Tyson ... pulling up to an after-party his company, Betr, is throwing in Dallas.

The influencer turned boxing superstar arrived at the party -- hosted by Jake with the help of the sportsbetting company he cofounded back in 2022 -- looking suave in a blue and white shirt with vibrant multicolored shorts.

Jake was joined by his GF, Olympian Jutta Leerdam -- pulling off a sporty chic ensemble made up of a black sports bra and matching leggings -- and his dog pal Thor.

Everyone seemed to raise a glass to Jake at the party ... not surprising since very few people have ever defeated the Baddest Man on the Planet.

Numerous celebs are expected to stop by the party tonight ... and, we know of a few who showed up early on -- including Amber Rose who hosted the Tyson-Paul fight on Netflix last night.

Artist Rob Prior was also on hand, live painting portraits of both Jake and Mike. Paul ended up stopping by, and actually purchased two pieces.

As you know ... Paul handily defeated Tyson in the eight-round bout -- winning all but one round against the 58-year-old legend. JP later explained he worried about seriously injuring Iron Mike.

The fight -- which more than 60 million households tuneed in to watch, according to the streamer -- marks Jake's 11th career win, and he's already got plans for his next brawl ... an MMA fight with Conor McGregor.