Surname Ио (Io 
, Iou 
, Ио 
) , in the world, is a common family name. The family name Ио is characteristic of Macao, where it is a common surname, Albania, where it is quite a rare surname, and Hong Kong. Not in comparison with a country's population, the name is most common in Indonesia, Myanmar, and Italy. Also, Ио is the forename as well as the last name.