Thomas Bartholin (born Oct. 20, 1616, Copenhagen, Den.—died Dec. 4, 1680, Copenhagen) was a Danish anatomist and mathematician who was first to describe fully the entire human lymphatic system (1652).
He and his elder brother, Erasmus Bartholin, were the sons of the eminent anatomist Caspar Bartholin. A student of the Dutch school of anatomists, Bartholin supported the English physician William Harvey’s theory of blood circulation. He taught at the University of Copenhagen (1646–61) and served as physician to King Christian V (1670–80).