Unni Maria Lindell is a Norwegian author, best known for her crime novels, who has also written a collection of poems and several children's and young adult books. Lindell worked as a journalist before she became an author. Her first book, Den grønne dagen ("The green day") was published in 1986. One of Lindell's most prominent characters is detective Cato Isaksen. Lindell was awarded the Mads Wiel Nygaards Endowment in 1998 and the Critics' Prize for the year's best children's or youth literature. In 1999 she received the Riverton Prize (Rivertonprisen), am annual literature award given to the best Norwegian detective story.