Anna Karin Larsson (later "Ahlström", 30 August 1941 – 21 September 2019) was a Swedish swimmer who 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. Individually, she was eliminated in the preliminaries of the 100 m and 400 m freestyle.