Seiji Yokoyama (?? ??, Yokoyama Seiji, March 17, 1935 – July 8, 2017) was a prolific Japanese incidental music composer from Hiroshima who was best known for his work on the Space Pirate Captain Harlock and Saint Seiya series.
He was a graduate student of Kunitachi College of Music.
He made his debut as a composer for the ending theme of The Adventures of Hutch the Honeybee in 1971.
He was known for his symphonic sound for many television programs.
On July 8, 2017, Seiji Yokoyama died from pneumonia.