Cognomen Alagan (Alagan 
) , worldwide, is quite a rare last name. The family name Alagan is characteristic of Malaysia, where it is quite a rare surname, Bahrain, and United Arab Emirates. Not in comparison with a country's population, the name is most common in Malaysia, India, and Sri Lanka. Very seldom, Alagan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Alagan | Saudi Arabia, Philippines, Sri Lanka, Malaysia, India |