Samuel Monroe Jr., best known for his work in the ’90s classic film “Menace II Society,” has been hospitalized … and the situation is serious.

Family tells TMZ … the actor is on life support in a SoCal hospital — and he’s battling meningitis. As for the prognosis, we’re told it’s unclear, and the family is getting daily updates.

Samuel’s mother posted about the situation on Facebook, saying in part … “God don’t make no mistakes, but he is gracious, and I am humbly asking for his mercy and grace for Sam. I love you, son, to the moon and back 100 times.”

The 52-year-old actor has appeared in a slew of films and TV shows, including “Tales from the Hood,” “Set It Off,” “The Players Club,” “Out All Night” and “NYPD Blue.” Samuel also appeared in “Don’t Be a Menace to South Central While Drinking Your Juice in the Hood,” the Wayans Brothers’ spoof of 1990s L.A.-based crime dramas.