Kosunen is a Finnish surname. Notable people with the surname include:
Allu Kosonen (1908–1965), composer, musician and pedagogue
Antti Kosunen (born 1965), entrepreneur
Jorma Kosunen (born 1950), politician and military commander
Kalevi Kosunen (born 1947), boxer
Olli Herman Kosunen (better known as H. Olliver Twisted; born 1983), singer
Rele Kosunen (brn 1962), singer
Svante Kosunen (1925–1988), singer