Family name Rey-Gagneux (Rey-Gagneux 
) , across the world, is an extremely rare cognomen. The surname Rey-Gagneux is habitual in Western Europe, particularly France, where it is an extremely rare surname. Parts of the name also exists independently as a first name Rey, and a last name Gagneux.
| VARIANT | COUNTRY |
|---|---|
| Rey-Gagneux | France |