Cognomen カイロ (Cairo 
, カイロ 
) , all over the world, is a common surname. The cognomen カイロ is habitual in Suriname, where it is a common surname, Uruguay, where it is quite a rare surname, and Egypt. Measured by absolute frequency, it is the most numerous in Egypt, Italy, and Argentina. Much less frequently, カイロ is the forename as well as the last name.