Cognomen Octavio Guillermo (Octavio Guillermo 
) , around the globe, is a very rare surname. The family name Octavio Guillermo is habitual in Latin America and the Caribbean, particularly Chile, where it is a rare surname. More prevalently, Octavio Guillermo is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Octavio Guillermo | Spain, Mexico, Chile, Ecuador, Peru |