Sakamoto was also known for his work with the pioneering electronic music band Yellow Magic Orchestra (YMO) which he co-founded.
Introduced to the piano as a toddler, Sakamoto lived for music. In high school, he rode on Tokyo commuter carriages so packed nobody could move, amusing himself by counting all the different sounds the train made along the way.
Sakamoto, who described classical musician Claude Debussy as his hero, studied ethnomusicology at the Tokyo National University of Fine Arts and Music, with particular interest in the traditional music of Japan's Okinawa prefecture as well as Indian and African musical traditions.
"Asian music heavily influenced Debussy, and Debussy heavily influenced me. So the music goes around the world and comes full circle," he told WNYC public radio in 2010.
Embracing electronic music, he and fellow studio musicians Haruomi Hosono and Yukihiro Takahashi formed YMO in 1978. The band's groundbreaking use of a vast array of electronic instruments brought both domestic and global success.
Sakamoto's first score was for the 1983 film Merry Christmas Mr Lawrence, in which he also played the commandant of a prisoner of war camp, starring alongside David Bowie. The score went on to win a BAFTA.
His most celebrated work was 1987's The Last Emperor - a film in which he also acted. The score won an Oscar, a Grammy and a Golden Globe.
Sakamoto, who was an anti-nuclear campaigner and environmental activist, took a break from work in 2014 for about a year to be treated for throat cancer. Though cured of that after years of treatment, he announced on his website in January 2021 that he had been diagnosed with rectal cancer.
In December 2022, Sakamoto gave what was clearly meant to be a farewell concert for his fans, broadcast online.
"My strength has really fallen, so a normal concert of about an hour to ninety minutes would be very difficult," he said in an online message several days before.
"As a result, I've recorded it song by song and edited it together so it can be presented as a regular concert - which I believe can be pleasurable in the normal way. Please, enjoy."
