Samuel Coster was a Dutch playwright.
Coster was the fifth child of Adriaen Lennaertz, sexton and carpenter, and Aeltgen Jansd. By around 1605, he was a member of the Amsterdam rederijkerskamer "De Eglantier". Presumably he was helped into the society by rich friends, but then got himself to Leiden University in 1607. He began as a student of the humanities, but he graduated in 1610 as a doctor in medicine. He was appointed a physician at the Hospital on his return to Amsterdam.
Coster for 10 years played a leading role in the literary life of Amsterdam, making his name in the theatre. "Teeuwis de boer", a comedy in all probability already written during his years in Leiden, was in 1612 put on by "De Eglantier". Inspired by the national anthem, Coster laid out in it comical motives and characters: a voluptuous man married with an old woman, a farmer opposite a city-dweller, a bragging Westfaals talking with a bald nobleman, and a sly and knowing French lawyer. In 1613 the "Spel van Tiisken vander Schilden" appeared, at first anonymous but later attributed to Coster on the basis of stylistic resemblance with other works of his.