Family name Gregorio Guillermo (Gregorio Guillermo 
) , all over the world, is a very rare cognomen. The surname Gregorio Guillermo is habitual in Chile, where it is a very rare surname, and Spain. More prevalently, Gregorio Guillermo is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Gregorio Guillermo | Ecuador, Spain, Chile, Peru, Costa Rica |
Gallo, Pincay, Gonzalez, Pincay Pisco, and Muñoz Zambrano