EXCLUSIVE

Jonathan Winters, the comedic film and TV actor who was huge in the '70s and '80s on shows like "Mork and Mindy," has died at age 87 ... TMZ has learned.

Winters died last night of natural causes in Montecito, Calif, around 6:30 p.m., surrounded by friends and family.

Winters' career began when he won a talent contest, which led to radio gigs and appearances at comedy clubs. He was a staple on the late night TV circuit for decades -- he was one of Jack Paar's favorite guests and a Johnny Carson regular -- and recorded several classic comedy albums.

He often performed in character ... the best known of which was Maude Frickert, the seemingly sweet old lady with a quick and acid wit. He also starred in one of the best comedies ever -- "It's a Mad, Mad, Mad, Mad World."

Winters suffered 2 nervous breakdowns in the late '50s and early '60s and was voluntarily institutionalized. He was diagnosed with manic depression. He spoke openly about it and even joked about it in his comedy act.

Winters -- who was Native American -- won the Mark Twain Prize for American Humor, which was presented to him at the Kennedy Center in Washington, D.C. in 2000.

Winters appeared in nearly 50 films and TV shows ... and was a regular on the Saturday morning children's television program "Hot Dog" in the '70s.