Sven Tito Achen (born July 29, 1922 in Buenos Aires, Argentina, died November 14, 1986) was an Argentinian-Danish writer and author on heraldry, co-founder of the Scandinavian Society of Heraldry (Societas Heraldica Scandinavica) and the first editor of the Scandinavian Heraldisk Tidskrift (Heraldry Journal) published in Denmark.