Cognomen Mercidieu (Mercidieu 
) , across the world, is a rare family name. The surname Mercidieu is characteristic of Haiti, where it is quite a rare surname, the Dominican Republic, where it is a rare surname, and France, where it is an extremely rare surname. Not in comparison with a country's population, this name is the most popular in Haiti, the Dominican Republic, and the United States. More prevalently, Mercidieu is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Mercidieu | Haiti, France, Dominican Republic, Brazil, United States |