Kari Juhani Suomi (born 29 March 1948 in Turku) is a Finnish linguist who was an assistant professor from 1985 to 2012 in the Department of Phonetics at the University of Oulu. He has researched English, Swedish and Finnish phonology.
His textbook Introduction to Speech Acoustics has been used for university teaching in Finnish phonetics, speech therapy and vocology since 1990.
His other two textbooks with Toivanen and Ylitalo are Fundamentals of Phonetics and Finnish Sound Theory, 2006, and Finnish Sound Structure: Phonetics, phonology, phonotactics and prosody, 2008.