Statens Järnvägar
Erik Lönnroth was the son of Magnus Lönnroth, District Secretary of Swedish State Railways in Gothenburg, and Gerda (Kjellberg) Lönnroth . He married in 1934 to Ebba Lagercrantz (1908-1980). They were the parents of Swedish literary critic, Lars Lönnroth and Swedish politician , as well as Louise Lönnroth, Ivar Lönnroth, and Peter Lönnroth.