László József Bíró ( Spanish: Ladislao José Biro);( 29 September 1899 – 24 October 1985) was the inventor of the modern ballpoint pen.
Bíró was born in Budapest, Hungary, in 1899 into a Jewish family. He presented the first production of the ballpoint pen at the Budapest International Fair in 1931. While working as a journalist in Hungary, he noticed that the ink used in newspaper printing dried quickly, leaving the paper dry and smudge-free. He tried using the same ink in a fountain pen but found that it would not flow into the tip, as it was too viscous. Working with his brother György, a chemist, he developed a new tip consisting of a ball that was free to turn in a socket, and as it turned it would pick up ink from a cartridge and then roll to deposit it on the paper. Bíró patented the invention in Paris in 1938.