Maj Sjöwall was a Swedish author and translator. She is best known for her books about police detective Martin Beck. She wrote the books in collaborative work with her partner Per Wahlöö.

Martin Beck is a fictional Swedish police detective and the main character in a series of ten novels by Maj Sjöwall and Per Wahlöö, collectively titled The Story of a Crime. Frequently referred to as the Martin Beck stories, all have been adapted into films between 1967 and 1994. Six were adapted for the series featuring Gösta Ekman as Martin Beck.