Kazumasa (written: 数正, 和正, 和昌, 和政, 一眞, 一正, 一将, 一存, 一政 or 員昌) is a masculine Japanese given name. Notable people with the name include:
, Japanese baseball player , Japanese musician , Japanese writer , Japanese weightlifter , Japanese samurai , Japanese samurai , Japanese samurai , Japanese footballer , Japanese baseball player Kazumasa Nagai (永井一正; 1929–2026), Japanese printmaker and graphic designer , Japanese singer-songwriter and composer , Japanese photographer , Japanese badminton player , Japanese ice hockey player , Japanese daimyō , Japanese footballer , Japanese samurai , Japanese footballer , Japanese boxer , Japanese footballer , Japanese baseball player