Avo Sõmer (born 1934) is an American musicologist, music theorist, and composer, of Estonian birth.
He majored in music education, piano performance, and composition at Wayne State University in Detroit, Michigan, followed by graduate studies at the University of Michigan where, in 1957, he earned an M. A. with a thesis on Monteverdi's madrigals, and then, in 1963, a PhD with a dissertation "The Keyboard Music of Johann Jakob Froberger".
He is best known for his analytical publications on early twentieth-century music, especially that of Debussy and the Estonian symphonist, Eduard Tubin, though his unpublished Ph.
As a composer, Sõmer participated in Karlheinz Stockhausen's composition studio at the Darmstädter Internationale Ferienkurse für Neue Musik in 1967, contributing the oboe part to Ensemble.
Instead, he adopted a style close to that of the late works of Béla Bartók, with just a glimpse of the string quartets of Elliott Carter.