Stanisław August Poniatowski (born Stanisław Antoni Poniatowski) was born on 17 January 1732 at Volchyn (Wolczyn), a small town in Brest district (now in the Kamenets district of the Brest Region). He was a descendant of Poniatowski magnate family, related to Czartoryski family. He was the son of Stanislaw, an influential politician and castellan of Krakow, and Konstancja née Czartoryska. He spent the first few years of his childhood in Gdańsk; afterward, his family moved to Warsaw.
Stanisław August Poniatowski was brought up in the environment close to the highest circles of power of Rzeczpospolita and since his youth was connected to the Czartoryski Familia, a very influential grouping in Rzeczpospolita. He travelled a lot, visiting England, Holland, France, and Germany and was under a strong influence of the European Enlightenment ideas.