Sallinen studied at the Sibelius Academy 1955-1960, with the teachers Aarre Merikanto and Joonas Kokkonen. After graduating, he was appointed as administrator of the Finnish Radion Sinfoniaorkesteri (1960-69). He also was the Secretary and member of the Board (1958-73), then Chairman (1971-73) of the Finnish Composers' Society; member of the board of TEOSTO (Finnish copyright society) from 1970-84, then Chairman from 1988-90; he also served for several years on the Board of the Finnish National Opera. He is a member of the Royal Swedish Music Academy and Honorary Doctor of the Universities of Helsinki and Turku. The Finnish Government made him Professor of Arts for life in 1981 - the first appointment of its kind, thus making it possible for him to devote all of his time to composing.
Sallinen has written 6 operas, 8 symphonies, a violin concerto and several chamber works. His most known operas include 'The Horseman', 'Kullervo' and 'The Red Line'. He has also composed the title track of Kronos Quartet's album 'Winter Was Hard'.