Johannes Heurnius (born Jan van Heurne; 4 February 1543 – 11 August 1601) was a Dutch physician and natural philosopher.

[3] Heurnius already had a reputation and good contacts with humanist scholars, and was appointed as senior to Gerardus Bontius, an earlier physician on the faculty.

[1] It is not clear, however, if the 1591 proposal by Heurnius and Bontius to implement practical teaching on the Paduan lines was accepted officially.

[1] After his father's death, Otto put together his lectures, published in the Opera Omnia, covering medicine both in theory and as a practical discipline.

He helped prepare one of the earliest translations of the Bible into Malay and was the first European to collect, document, and record many of the South African Cape plants.