Mio or Mío is a surname. Notable people with the surname include:
Atsushi Mio (born 1983), Japanese former footballer Chiara Mio (born 1964), Italian business executive and professor Daniel Mio (1941–2021), French politician and teacher Eddie Mio (born 1954), Canadian former National Hockey League goaltender Eriberto Arroyo Mío (1943–1989), Peruvian politician Giovanni de Mio (after 1510–c. 1570), Italian painter and mosaicist Vangjush Mio (1891–1957), Albanian painter Washington Mio, 20th-21st century mathematician