László József Bíró (Hungarian pronunciation: [ˈlaːsloː ˈjoːʒɛf ˈbiːroː]; born László József Schweiger; 29 September 1899 – 24 October 1985), Hispanicized as Ladislao José Biro, was a Hungarian-Argentine inventor who patented the first commercially successful modern ballpoint pen. The first ballpoint pen had been invented roughly 50 years earlier by John J. Loud, but it was not a commercial success.