Thomas Seget (Seton?, 1569 – Amsterdam, 1627) was a Scottish poet who wrote in Latin. Seget is first recorded as a convert from Calvinism to Catholicism, attending the Scots College at Louvain in 1596, but did not stay long. Carrying a letter of recommendation from Justus Lipsius, the Flemish humanist, he travelled to Italy where he met Galileo in 1599. He travelled further through Europe, making the acquaintances among others of Kepler in Prague. He also corresponded with the Polish poet Szymon Szymonowic, and other Polish connections included his stay at the University of Altdorf 1614–1616 at the same time as the Socinian activity there around Samuel Przypkowski.