The Oscar-nominated actor died Thanksgiving Day of natural causes, Zap2it.com reported Friday.
Morita first gained public attention as Arnold, the diner owner on "Happy Days," but he shot to stardom and received an Oscar nomination for his role as teacher Kesuke Miyagi in 1984's "Karate Kid."
Born Noriyuki Morita in Isleton, Calif., the actor battled spinal tuberculosis as a youth, Zap2it.com said. After undergoing spinal fusion surgery at at 11, he went straight from the hospital to an World War II Japanese internment camp.
He left his family's restaurant business to work for an aerospace company, but he heard showbiz calling so he changed his name to Pat and left to try his luck in Hollywood.
He appeared in a slew films including "Thoroughly Modern Millie," "Honeymoon in Vegas," "Spy Hard" and Disney's "Mulan" films, in which he provided the voice of the emperor.
Among his TV credits were "Love, American Style," "Green Acres," "M*A*S*H," "Sanford and Son," "Ohara," "Mr. T and Tina," "The Hughleys" and the cartoon, "Robot Chicken."
He is survived by his wife, Evelyn, and three daughters.