Nick Saban is calling on Ray Rice to teach his Alabama players an important lesson ... saying he had the ex-NFL star give a speech to the Tide "about how to treat the opposite sex."

Rice has been preaching to players and schools all over the country since he was booted from the NFL after TMZ Sports posted video of him punching his then-fiance in the face in a hotel elevator in 2014.

Saban clearly thinks the former running back has a valuable message he can relay to his team ... 'cause the Bama head coach invited the 32-year-old out to practice this week.

"He’s going to be here as a Title IX speaker to the team [Thursday night], which I think is a good thing for our players," Saban said.

"He’s obviously going to talk about how to treat the opposite sex and having the proper respect for other people."

Saban added, "I think that’s important to relationships. It’s important as a person to be able to do those things in a very respectful manner."

Rice has made countless attempts to try to make up for his massive misstep 5 years ago ... even offering to help Browns running back Kareem Hunt after he was caught on camera kicking a woman last year.

Seems Rice is finding success on his redemption tour ... coaches continue to bring him on to speak ... and in his return to Baltimore last year, he was wildly cheered.