Martha Maria Norelius (January 22, 1909 – September 25, 1955) was a Swedish-born American competition swimmer, Olympic gold medalist, and former world record-holder in five different freestyle swimming events.

[2][4] Norelius won the gold medal in the women's 400-meter freestyle in 1924, setting a new Olympic record (6:02.2), and edging fellow Americans Helen Wainwright (6:03.8) and Gertrude Ederle (6:04.8).

First, in individual competition, she won the women's 400-meter freestyle, breaking her own record with a new world mark of 5:42.8, and defeating Dutch swimmer Marie Braun by fifteen seconds.

Between 1925 and 1929, Norelius won eleven individual Amateur Athletic Union (AAU) titles and set at least 19 world and 30 American records.

[6][7] Norelius died in 1955, only 46 years old, following gall bladder surgery[8] and was buried in Bellefontaine Cemetery.