Dagmar Hagelin (29 September 1959 - disappeared on 27 January 1977) was a 17-year-old Swedish-Argentine girl who disappeared during the Dirty War on 27 January 1977, and is presumed to have been arrested by security forces in El Palomar, Buenos Aires,[1] Argentina, and murdered in a case of mistaken identity.

[2] Dagmar's father, Argentine-Swedish businessman Ragnar Hagelin, worked for several decades to have the responsible people brought to justice, accusing Alfredo Astiz.

[3] Hagelin and Svante Grände are the two known Swedish victims of the Dirty War during Argentina's military regime.

[8][9] It is believed that Dagmar was a victim of mistaken identity when on 27 January 1977, she went to visit a friend in the suburbs of Buenos Aires.

Hagelin, who had decided to visit her friend on a spur of the moment, was approached by the forces and shot when she tried to escape.