Thomas Platter the Younger (; ; c. 24 July 1574 in Basel â 4 December 1628 in Basel) was a Swiss-born physician, traveller, and diarist, the son of the humanist Thomas Platter the Elder. He was a professor of anatomy, botany, and medicine at the University of Basel, as well as the city physician for Basel.
Platter kept a diary from 1595 to 1600. Platter recounts his life as a medical student in Montpellier and his travels in France, Spain, Flanders, and England. He describes many aspects of late sixteenth-century European culture: medical education (including dissections), street and carnival life in Barcelona, European theater, and the slave trade.
On 21 September 1599, "at about two o'clock," Platter and his older half-brother Felix Platter saw an early production of Julius Caesar at the Globe Theatre in London. Platter's account provides Shakespeare scholars with evidence for the dating of that play.