Martin Widmark was born in 1961 in Sweden and lives in Stockholm with his family. He has worked as a middle school instructor and a Swedish teacher for immigrants, but he is now a full-time children's book author. Over his career, he has also written several text books. He is fascinated by life's little oddities and anything unique, from food and music to languages and people.

Widmark is considered a literary giant of contemporary children's fiction in Sweden. His Halvdan Viking, Nelly Rapp and LasseMaja (translated to The JerryMaya Detective Agency) series are consistently on the best seller lists and have received critical acclaim. His books have been translated into more than 20 languages, and he has been awarded the children's own book award 11 times for the LasseMaja titles.