Gustafva Sofia Hjärne (4 July 1780 - 6 December 1860), was a Finnish baroness, writer and salon holder.
Sofia Hjärne was the central figure in one of Finland's earliest literary salons. During the Finnish War in 1808-1809 Sofia Hjärne, according to certain sources, was instrumental in averting a battle by achieving the peaceful handover of the stronghold of Sveaborg near Helsinki to the Russians. In 1831, she published the novel Tawastehus Slott. En Romans fra Birger Jarls af Bjelbo tidehwarf (P) anonymously. She also translated two plays and wrote poems for almanacs and newspapers anonymously.