Tadeáš Hájek, Czech physician and astronomer (died 1600)

Tadeáš Hájek of Hájek, also known by Latinized names Thaddaeus Hagecius ab Hayek and Thaddeus Nemicus, was a naturalist and astronomer from Bohemia. He was a personal physician of the Holy Roman Emperor Rudolf II and an astronomer in the Kingdom of Bohemia.