Theodor Kerckring
![The 22-year-old Theodore Kerckring by Jurgen Ovens (1660).[1]](/uploads/202501/22/BolKerckring5126.jpg)

Theodor Kerckring or Dirk Kerckring (sometimes Kerckeringh or Kerckerinck) (baptized 22 July 1638 – 2 November 1693) was a Dutch anatomist and chemical physician.
Kerckring was born as the son of the Amsterdam merchant and VOC captain Dirck Kerckring and Margaretha Bas (daughter of Dirck Bas, a former mayor of Amsterdam). In the second half of the 1650s he was a pupil at the Latin School in Amsterdam of Franciscus van den Enden (at the same time as the philosopher Benedictus de Spinoza), before studying medicine at Leiden University under Franciscus Sylvius. Around 1660 he was painted by Jurgen Ovens. In 1667 he was visited by Cosimo III de' Medici, interested in new developments in science and curious to see his collection of anatomical objects.