Dagmar Hagelin (September 29, 1959 - disappeared on January 27, 1977) was a 17-year-old Swedish-Argentine girl who disappeared during the Dirty War on January 27, 1977, and is presumed to have been arrested by security forces in El Palomar, Buenos Aires, Argentina, and murdered in a case of mistaken identity.
Dagmar's father, Argentine-Swedish businessman Ragnar Hagelin has since worked to have the responsible people brought to justice, accusing Alfredo Astiz.Hagelin and Svante Grände are the two known Swedish victims of the Dirty War during Argentina's military regime.In October 2011, Alfredo Astiz was sentenced to life imprisonment for crimes against humanity in Argentina between the years of 1976 and 1983.
Dagmar's father, Ragnar Hagelin commented to Swedish media on the sentence that he, "couldn't describe the happiness he felt that after 34 years of struggles, Dagmar’s killer would finally pay for his crimes".
In 2010, a pilot named Julio Poch was indicted for the murder of Hagelin.
Ragnar Hagelin resided in Stockholm, Sweden, until his death in 2016.