Surname Guillermo Oswaldo (Guillermo Oswaldo 
) , globally, is an extremely rare last name. Predominantly, Guillermo Oswaldo is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Guillermo Oswaldo | Costa Rica, Spain, Ecuador, Argentina, Peru |
Reyes, Castro, Marrujo, Rengifo, Mera Pelaez, Huacachi, Mier Patino, Malpartida, Campos Ayala, Perez Carvajal, Morocho Chango, and Flores Martinez