Gerard van Swieten (1700 - 1772) was a Dutch - Austrian physician.

Van Swieten was born in Leiden. He was a pupil of Hermann Boerhaave and became in 1745 the personal physician of the Austrian Empress Maria Theresa. In this position he implemented a transformation of the Austrian health service and medical university education. He founded a botanical garden, a chemical laboratory and introduced clinical instruction.

Especially important is his part in the fight against superstition during the enlightenment, particularly in the case of the vampires, that were reported from villages in Eastern Europe in the years between 1718 and 1732. After the last of the wars against the Turks in 1718 some parts of the land, e.g., Northern Serbia and a part of Bosnia, went to Austria. These parts were settled with refugees that had the special status of duty-free farmers. But for that they had to take care of the agricultural development and secure the frontier. Because of that, the reports about the vampires reached for the first time the German speaking area. In the year 1755 Gerard van Swieten was sent by Empress Maria Theresa to Moravia to investigate the situation relating to vampires. He viewed the vampire myth as a "barbarism of ignorance" and his aim was to eradicate it.

He investigated it very thoroughly, and wrote a rational report, Abhandlung des Daseyns der Gespenster (or Discourse on the Existence of Ghosts), in which he offered an entirely natural explanation for a belief in vampires. He explained the unusual states in the graves with possible causes like processes of fermentation and lack of oxygen as a reason for preventing decomposition. Characteristic for his opinion is this quotation from the preface to his essay of 1768: “… that all the fuss doesn't come from anything else than a vain fear, a superstitious credulity, a dark and eventful imagination, simplicity and ignorance among the people.” Some other physicians supported his theory or even found out other reasons for the frequent deaths in the villages, e.g., epidemics.

Therefore Gerard van Swieten was one of the most important fighters against the superstition of the "simple" people. Because of his report, Empress Maria Theresa enacted an edict about vampires that prohibited all traditional processes such as impalement, beheading and burning of dead bodies.

Beside his medical activities, Gerard van Swieten was also active as a reformer. Especially the censorship was organized in a different way under his direction. He drove out the Jesuits that were in charge of the censorship before and carried out a centralization of the censorship that was only partly successful. He also tried to use scientific and rational aspects for the judgement of literature.

Gerard van Swieten was the father of Gottfried van Swieten, who had his own career in government service and is remembered as a patron of Haydn, Mozart, and other composers.

Im May, 1749 van Swieten was elected a Fellow of the Royal Society. In 1751, he was elected a foreign member of the Royal Swedish Academy of Sciences.

A genus of mahogany was named after Gerard van Swieten, Swietenia, by Nikolaus Joseph von Jacquin.

The Frank - van Swieten Lectures, an international course about strategic information management in hospitals that is organized by TU Braunschweig, University of Amsterdam, University of Heidelberg, UMIT at Hall near Innsbruck and Fachhochschule Heilbronn are named after him.