Yoshiaki Onishi (大西 義明, Onishi Yoshiaki, born 1981 in Hokkaido, Japan) is a Japanese-American composer, conductor, and clarinetist. He is a recipient of several international prizes and honors. He currently resides in the United States. In 2018 he won a Guggenheim Fellowship and is currently Assistant Conductor of the New Music Ensemble at the University of Missouri School of Music.