Ex-USC Tight End -- 6 Years In Prison ... For Violent Robbery Spree

The former USC football player accused of going on a violent 5-hour rampage in Los Angeles back in January has just been sentenced to 6 years in state prison ... TMZ Sports has learned.

We broke the story ... Bryce Dixon -- a 6'5" tight end who was kicked off the football team in 2015 -- was initially arrested for carjacking on Jan. 19th.

Officials say the 19-year-old hooked up with an ex-LSU football player and went on a late-night crime spree near the USC campus ... committing 7 violent robberies in 5 hours. In one case, officials say the men held a knife to a woman's throat.

Dixon and the other man were both charged with multiple counts of robbery -- along with carjacking and assault with a deadly weapon.

Now, we've learned ... Dixon struck a plea deal ... in which he pled no contest to 1 count of carjacking, 2 counts of 2nd degree robbery and admitted using a knife during the rampage.

Officials say he was sentenced to 6 years in state prison -- and will begin his sentence immediately.