Tito Ortiz -- Screw UFC ... Bellator Gots My Back Now!

MMA legend Tito Ortiz is no stranger to bad breakups ... and tells TMZ he's moved on from the UFC because he knows Dana White ain't lookin' to bury the hatchet anytime soon.

Dana and Tito famously trashed each other following Tito's last UFC fight back in 2012 ... and Ortiz has since struck a deal with Bellator, a rival MMA organization.

In fact, Ortiz is set to fight fellow UFC-defector Rampage Jackson under the Bellator banner in November.

But, when we asked Tito if there was any chance at patching things up with his former boss and returning to the UFC ... Tito simply explained, "Nah, Dana holds grudges."

It ain't the first time Tito and Dana have gone after each other -- they also tore each other apart back in 2008 ... and Tito left the UFC ... only to return one year later.