Last name סיו (Sio 
, סיו 
, Sjöö 
) , all over the world, is a common family name. The last name סיו is characteristic of Macao, where it is a common surname, Sweden, where it is quite a common surname, and Mozambique, where it is quite a rare surname. Measured by absolute frequency, it is the most numerous in Macao, Mozambique, and Philippines. Likewise, סיו is the forename as well as the last name.