The Morioka Daisan High School (岩手県立盛岡第三高等学校, Iwate-kenritsu Morioka Daisan Kōtōgakkō), commonly referred to as Morioka Third High School or San-Kō, is located in Morioka, Iwate Prefecture, Japan. It is the third oldest public high school in the city, founded in 1963. It has a student body of approximately 1,000 students.