Kalevi Aho (born 9 March 1949 in Forssa, Finland) is a Finnish composer.
Born in Forssa, he studied composition at the Sibelius Academy under Einojuhani Rautavaara, receiving a diploma in 1971. He continued his studies for a year in Berlin with Boris Blacher. His teaching positions include music theory at the University of Helsinki from 1974 to 1988, and a professorship at the Sibelius Academy from 1988 to 1993. He became composer-in-residence for the Lahti Symphony Orchestra in 1992, and conductor Osmo Vänskä has recorded many of his recent large-scale works with the orchestra. Aho has worked as a freelance composer, with a state scholarship, since 1993. As of May 2006, he lives in Helsinki.
Known principally as a composer of large-scale works, to date Aho has composed thirteen symphonies several concerti, and two operas. His chamber music includes several sonatas and three string quartets. He first came to fame with his first symphony (1969) and second string quartet (1970). His works of this time showed such neo-classical traits as a preoccupation with counterpoint (particularly fugues), and stylized renderings of older forms, such as the waltz. During the next decade he wrote in modernist and post-modernist styles. His use of irony and juxtaposition of contrasting moods and musical styles and genres has been compared to Gustav Mahler and Alfred Schnittke.  His early music also shows the influence of Dmitri Shostakovich.