Keiichi Oku (奥 慶一, Oku Keiichi, born October 14, 1955 in Shiga Prefecture, Japan) is a Japanese keyboardist, composer, and arranger. He was the keyboardist in the Japanese band Spectrum from 1979-1981. In 2009, he won the JASRAC International Award for the background music used in the Ashita no Nadja anime television series from Toei Animation.