Paul-Ferdinand Gachet (30 July 1828 – 9 January 1909) was a French physician most famous for treating the painter Vincent van Gogh during his last weeks in Auvers-sur-Oise.

He was an amateur painter, signing his works "Paul van Ryssel", referring to his birthplace: Rijsel is the Dutch name of Lille.

His family moved to Mechelen, whence Gachet's father was transferred in 1844/1845 to start a new branch of the firm he was working for.

[2] While a student at the University of Paris, he learned drawing in his spare time, and collected paintings by Gustave Courbet and Édouard Manet.

[6] In 1872 he bought a house in Auvers-sur-Oise, a village around 27 kilometres (17 mi) from Paris that was popular with artists.

He was released from the asylum on 16 May 1890, but continuation of medical attention was required, which included Van Gogh being under supervision.

According to van Gogh biographer Wilfred Arnold, "there was not much else available to any physician of the day which could have reversed the course of Vincent's illness,"[11] and he summarizes the medical treatment that Van Gogh received from his various doctors thus: "The overall assessment is rather that they did as well as expected with an unfamiliar disease and a difficult patient.

Gachet is prominently featured in Maurice Pialat's 1991 film Van Gogh where he is played by Gérard Séty.