Former NFL great Charles "Bubba" Smith -- who later starred in the "Police Academy" movies -- was found dead today in his Los Angeles home. He was 66 years old.

Law enforcement officials tell TMZ ... LAPD received a 911 call at 12:54PM today -- and officers responded to his home in the Baldwin Hills area. The fire department also responded and we're told Smith was dead when authorities arrived.

The L.A. County Coroner is on the scene investigating. We're told, at this point, authorities think he died of natural causes.

According to the L.A. Times, Bubba's caretaker discovered the body and called police. His autopsy will be performed later this week.

Bubba -- a towering 6'7" -- spent 9 seasons as a defensive end in the NFL, playing for the Baltimore Colts, Oakland Raiders, and Houston Oilers.

He won Super Bowl V with the Colts -- but is most famous for his role as the giant and lovable Moses Hightower in 6 of the "Police Academy" movies.

