Osornio is a surname. Notable people with the surname include:
Agustina López de Osornio (1769–1845), Argentine noblewoman Arturo Osornio (born 1953), Mexican politician Clemente López de Osornio (1720–1783), Spanish military leader Enrique Cornelio Osornio Martínez de los Ríos (1868–1945), Mexican politician and general Erick Osornio (born 1983), Mexican taekwondo practitioner Francisco López Osornio (c.1640-1700s), Spanish military leader Francisco López de Osornio Merlo (1681–1750), Spanish military leader and landowner Ramón López de Osornio (1685–1750), Spanish landowner, who served as Captain of provincial militias of Buenos Aires Saturnino Osornio (1896–1976), Mexican governor of Querétaro from 1931 to 1934