Yvar Emilian Mikhashoff (born Ronald Mackay; March 8, 1941 in Troy, New York – October 11, 1993 in Buffalo, New York) was an American virtuoso pianist and composer. He is best known for his performance of contemporary classical music. From 1983 to 1991 he commissioned no fewer than 127 tangos for solo piano from 127 composers. A complete archive of Mikhashoff's works is held by the Music Library of University at Buffalo Libraries at the University at Buffalo, The State University of New York.