Worldwide, Justo Gerardo (Justo Gerardo 
) is a very rare boy's first name. The first name Justo Gerardo is habitual in Latin America and the Caribbean, particularly Peru, where it is a very rare boy's name. Very seldom, Justo Gerardo is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Justo Gerardo | Costa Rica, Spain, Chile, Ecuador, Peru |