Saint Eskil (11th century) was an Anglo-Saxon monk particularly venerated during the end of the 11th century in the province of Södermanland, Sweden. He was the founder of the first diocese of the lands surrounding Lake Mälaren, today the Diocese of Strängnäs. He is the patron saint of Södermanland and the Diocese of Strängnäs. Saint Eskil was buried in his monastery in Tuna. Strängnäs was later converted to Christianity and the diocese that Eskil had created in Tuna was moved or reestablished in Strängnäs.