NFL's Justin Hunter -- Not Guilty ... In Bar Brawl Trial

Justin Hunter's off the hook for a MASSIVE bar brawl back in July ... 'cause a Virginia judge found the Tennessee Titans wide receiver not guilty ... TMZ Sports has learned.

Hunter was charged with misdemeanor assault and battery after allegedly breaking a man's jaw at a Virginia Beach bar over July 4th weekend ... hospitalizing the victim for two days.

The case went before a judge Tuesday ... and after only 4 hours, Hunter was found not guilty.

A spokesperson for the prosecutor's office told us they disagree with the finding, but respect the ruling.

"It is our belief we had sufficient evidence to prove the case beyond a reasonable doubt."