Ragnheiður Ragnarsdóttir, also known as Ragga Ragnars[1] (born 24 October 1984) is an Icelandic actress and former swimmer, who specialised in sprint freestyle events.

After retiring from swimming, Ragnheiður studied acting and played the role of Gunnhild on the TV series Vikings from 2018 to 2020.

[7][8] At the 2008 Summer Olympics in Beijing, Ragnheiður qualified for the second time in the same swimming program as the previous Games.

[9][10][11] In the 100 m freestyle, she was reassigned in heat three against seven other swimmers, including Hong Kong's Hannah Wilson and Bahamas' Arianna Vanderpool-Wallace.

[12] In the 50 m freestyle, Ragnheiður finished fourth in heat eight by 0.13 of a second behind Jamaica's Natasha Moodie, clocking at 25.82.