Karl Martino Widmark (born 19 March 1961)[1] is a Swedish children's writer and teacher.

His books about LasseMaja junior mysteries, in English named The Whodunit Detective Agency, have been translated from Swedish into 34 languages.

[citation needed] Martin Widmark is involved in issues concerning reading comprehension of children and young people and was the initiator of the project A Reading Class (En läsande klass[2]) which was launched in 2012, together with several publishers and the Junibacken Foundation.

He has made more than a thousand visits to different schools and classrooms and was in August 2014 awarded the Swedish government's medal Illis Quorum for his books and work with children and young people's reading.

Widmark made his debut with the book "To catch a woman with a mental disorder" (Att fånga en tiger[3]).