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, 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.