TMZ Sports talked to Bellator's 37-year-old light heavyweight and heavyweight champ -- who's taking on Vadim Nemkov at Bellator 244 Friday night -- about his history with Jones ... and Bader made it very clear he's got revenge on his mind.

"I would love to have that [Jon Jones] fight. It'd be a big fight," Bader says.

"Hell yeah, I would love to do some sort of cross-promotion with him or any of the guys over there."

Remember, Jones submitted Bader via a guillotine choke during the 2nd-round of their UFC 126 fight nearly a decade ago.

RB admits he was a 1 trick pony back then ... but that ain't the case anymore.

"We fought way back in 2011 and whatnot. I had no idea what I was doing back then besides wrestling. Mentality, skill set, physicality, it's all 100% different."

Proof?

Bader hasn't lost since 2016, has 2 belts, and has wins over Fedor Emelianenko, Ovince St. Preux, and Rashad Evans.

As exciting as the thought is of a UFC-Bellator cross-promotion featuring 2 elite fighters ... the reality is, it probably ain't gonna happen.

However, former top 5 ranked UFC light heavyweight Corey Anderson just signed with Bellator ... and he's in Bader's division.

So, does Ryan think Anderson's worthy of jumping the line and getting an immediate crack at his title??