Guy-Crescent Fagon (11 May 1638 – 11 March 1718) was a physician and botanist. He came from nobility and his great uncle, Guy de La Brosse, had founded the Royal Gardens. Fagon was director of the gardens too. His significance in botany is reflected in the genus Fagonia being named after him. He also acted as the physician of Louis XIV of France. In 1669 he was made an honorary member of the French Academy of Sciences. He wrote about the health of the royal family. He lost his position as head physician after Louis XIV's death, which was somewhat customary after a king died, but he also received criticism for how he had dealt with the King's final illness. People thought his methods were proposterous, that he bled his patients to death. He was thought to have killed Young Duc de Bretagne and the beloved Marie Adelaide. Despite this he remained in charge of the Royal Garden until his death in 1718.
^Remarques sur la santé du roy: Journal de santé de Louis XIV : précédé de la lancette et le sceptre par Stanis Perez / écrit par Vallot, Daquin et Fagon ; édition établie par Stanis Perez ; précédé de La lancette et le sceptre par Stanis Perez.Grenoble : Millon, c2004. ISBN 978-2-84137-159-4