Cognomen Ratagan (Ratagan 
) , all around the world, is a very rare last name. The family name Ratagan is habitual in Thailand, where it is a very rare surname, Philippines, where it is an extremely rare surname, and the United States. Not in comparison with a country's population, it is commonest in Thailand, the United States, and India. Also, Ratagan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ratagan | India, United States, Thailand, Philippines |