John J. Loud
On October 30, 1888, the first ballpoint pen or we have commonly known as ball pen or pen was patented in the United States of America with US patent #221676. John J. Loud from Massachusetts is the inventor of the first ballpoint pen. According to some sources, he was trying to invent a pen that can write on leather and on rough surfaces, then he comes up with the ball “tipped” pen.
https://theballpointpens.com/who-invented-the-ballpoint-pen/
László Bíró patented what is considered the first ballpoint pen in 1938, though he had been developing it for almost a decade beforehand with his brother György.
In 1931, they launched their ballpoint pen at the Budapest International Fair. Seven years later, in 1938, the Bíró brothers obtained patents in Britain and France and went to work to start selling their new ballpoint.
https://www.dayspringpens.com/blogs/the-jotted-line/who-invented-the-ballpoint-pen-history