Surname Mercilien (Mercilien 
) , around the globe, is a very rare cognomen. The last name Mercilien is habitual in Northern America, particularly the United States, where it is an extremely rare surname. More frequently, Mercilien is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Mercilien | Democratic Republic of the Congo, Mexico, United States, Brazil, Venezuela |