Cognomen Décimus (Décimus 
) , globally, is an extremely rare surname. The cognomen Décimus is habitual in Western Europe, particularly France, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Décimus | France |
|
yoann décimus Sprint track and field athletic, FR (b. 1987) |
|
| georges décimus FR (b. 1955) |
|