Anna Karin Larsson (later "Ahlström", 30 August 1941 – 21 September 2019) was a Swedish swimmer. He won a bronze medal at the 1958 European Aquatics Championships in the 4×100 m freestyle relay. She competed in the same event at the 1956 and 1960 Summer Olympics and finished sixth in both games. She was eliminated in the preliminaries of the 100 m and 400 m freestyle.