Leena Katriina Lehtolainen (born 11 March 1964) is a Finnish crime novelist, best known for her series of novels about the policewoman Maria Kallio.
Lehtolainen was born in Vesanto, in the Northern Savonia region of Finland. Her first novel was released when she was only 12 years old. She studied literature in Helsinki until 1995 and has been writing crime novels since 1993. Since about 2007 she has written other genres of books. Her works have been translated into numerous languages, including Spanish, Dutch, Chinese, Lithuanian, Polish, French, Swedish, German, Estonian and Czech. Leena Lehtolainen is married to Mikko Lensu and she has two children (Konsta Johannes, born in 1991 and Otso Olavi born in 1994). She lives in Degerby, west of Helsinki.