Surname Eustáchio (Eustáchio 
) , throughout the world, is an extremely rare cognomen. The surname Eustáchio is habitual in Latin America and the Caribbean, particularly Brazil, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Eustáchio | Brazil |
| eustáchio portella nunes filho (b. 1929) |
|