Olli Ilmari Mäenpää (born 2 November 1950 in Perniö, Finland) has been Professor of Administrative Law at the University of Helsinki since 1992 and previously held the same position at the University of Turku (1982–1992). He was a judge at the Supreme Administrative Court of Finland in 1994 and 2006 and from 1999 to 2003 was chair of the Council for Mass Media in Finland. He graduated from Helsinki University with a Master of Laws degree in 1974.