Cognomen Fiac (Fiac 
) , around the globe, is a very rare surname. The last name Fiac is habitual in Israel, where it is a very rare surname, Spain, and Brazil, where it is an extremely rare surname. Much more prevalently, Fiac is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Fiac | Brazil, Spain, Israel, Democratic Republic of the Congo |