Kari Korhonen (born July 24, 1943 in Sotkamo) is a Finnish mycologist and forest pathologist, known for his studies of fungi causing root rot.
From the start his research concentrated on the forest pathogen fungi then known as Heterobasidion annosum and Armillaria mellea.
During his career over 40 years he collected more than 4000 isolates of these species in Scandinavia, Germany, Italy, Greece, USA, Canada, Estonia, Belarus, Siberia and China.
Korhonen has published more than 50 scientific papers in international journals and edited books, almost all dealing with root rot fungi and their antagonists.
For his pioneering work, he received an honorary doctorate from the University of Monaco of Bavaria in 1992.