Divine, the 300-pound transvestite star of ''Pink Flamingos,'' ''Hairspray'' and other John Waters films, was found dead yesterday morning in his room at the Regency Plaza Hotel in Los Angeles. He was 42 years old.

The Los Angeles County Coroner's office is investigating the cause of death. According to John West, a spokesman for ''Hairspray,'' Divine died of a heart attack.

Divine, whose real name was Harris Glenn Milstead, became a cult figure as Mr. Waters's longtime leading performer. He generally portrayed garishly dressed women.

Mr. Milstead was born in a suburb of Baltimore on Oct. 19, 1945. He met Mr. Waters in high school, and the two became ''refugees from the fraternity and sorority life,'' Mr. Waters once said. He took the name Divine while acting in such early films by Mr. Waters as ''Roman Candles'' (1966), ''Eat Your Makeup'' (1968), ''Mondo Trasho'' (1969) and ''Multiple Maniacs'' (1970), and first gained relatively widespread attention in ''Pink Flamingos'' - a 1972 film that became a classic of studied bad taste.