Gerard Blasius

Gerard "Gerrit" Leendertszoon Blasius (1627–1682) was a Dutch physician and anatomist. He was born in Amsterdam and was the eldest son of Leonhard Blasius (died 1644), who had worked as an architect in Copenhagen. Gerard started his studies there, but the family moved to Leiden after his father died.

Around 1655, Blasius became a physician in Amsterdam. In October 1659, he was appointed to the Athenaeum Illustre but without being paid. In the next year, he became Amsterdam's first professor in medicine. At his home or in the hospital, corpses were dissected. In 1661, he claimed the discovery of Stensen's duct made by his pupil Nicolas Stensen.

Blasius had married Cornelia van Ottinga in 1653. His younger brother was the poet Joan Blasius.

Blasius died in Amsterdam in 1682.