Nopcsa was born in 1877 in Déva, Transylvania, Kingdom of Hungary (today Deva, Romania), to the Hungarian Nopcsa aristocratic family of Romanian origin. He was the son of , a member of the Hungarian Parliament. In 1895 Nopcsa's younger sister Ilona discovered dinosaur bones at the family estate at Szacsal (today part of Sânpetru, Sântămăria-Orlea, Romania). He shared the bones with Professor Eduard Suess, who encouraged him to study them. Following the professor's advice, he started studying geology at the University of Vienna in 1897, where he quickly advanced in his studies. He gave his first academic lecture in 1899 at the age of twenty-two. He acquired a PhD in geology in 1903 from the university; his doctorate focused on geologically mapping the area surrounding the family estate.