Masashi Sada (さだ まさし, Sada Masashi, born 10 April 1952) is a Japanese singer, lyricist, composer, novelist, actor, and a film producer.
Sada formed the folk duo Grape with Masami Yoshida in 1972, and they made their debut as recording artists a year afterward. The pair rose to fame owing to the hit song "Shourou Nagashi" (精霊流し) composed by Sada, which peaked at the number-two position on the Japanese Oricon chart in 1974. They broke up in 1976, after producing some hit singles including "En-kiri Dera" (縁切寺) and "Muen Zaka" (無縁坂).
Sada released his first solo album entitled Kikyorai shortly after Grape's dissolution. Following the commercial success of the number-one hit single "Amayadori" (雨やどり, Shelter from the rain) in 1977, he enjoyed a recording career as one of the most popular Japanese male artists during the late 1970s and the first half of the 1980s.
Throughout his career as a musician, Sada released over 35 solo albums and 70 singles, and multiple live albums or compilations. Since the release of Shourou Nagashi, published in 2001, Sada has also worked as a novelist.