Joonas Kokkonen (pronounced [ˈjoːnɑs ˈkokːonen] ⓘ; 13 November 1921 – 2 October 1996) was a Finnish composer.

Joonas was born in Iisalmi, Finland, but spent the latter part of his life in Järvenpää at his home, which was known as Villa Kokkonen, designed by Alvar Aalto and finished in 1969.

He received his education at the University of Helsinki, and later at the Sibelius Academy, where he afterwards taught composition; his students there included Aulis Sallinen.

[1] In the third style period Kokkonen wrote the music that made him internationally famous: the last two symphonies, the ...durch einen Spiegel for twelve solo strings, the Requiem, and the opera The Last Temptations (1975) (Viimeiset kiusaukset), based on the life and death of the Finnish Revivalist preacher Paavo Ruotsalainen.

The opera is punctuated with chorales which refer back to Johann Sebastian Bach, and which are also reminiscent of the African-American spirituals used for a similar purpose in Michael Tippett's oratorio A Child of Our Time.