Cognomen Alerto (Alerto 
) , all over the world, is a very rare surname. The surname Alerto is habitual in Spain, where it is a very rare surname, Philippines, where it is an extremely rare surname, and Venezuela. Not in comparison with a country's population, it is the most numerous in Spain, Philippines, and Mexico. More frequently, Alerto is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Alerto | Colombia, Philippines, Spain, Brazil, Mexico |