Johann Conrad Barchusen, originally Barkhausen, sometimes Barchausen (March 16, 1666 Horn, Principality of Lippe, Germany - October 2, 1723, Utrecht, Netherlands) was a pharmacist, chemist, physician and professor.
At Universiteit Utrecht, he was the first person to teach chemistry as a specific subject (not just as part of medicine).
He published four textbooks on chemistry and two on medicine.