'Menace II Society' Actor Samuel Monroe Jr. on Life Support

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 for the past three days -- 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.