Worldwide, William Maximiliano (William Maximiliano 
) is a very rare boy's forename. The first name William Maximiliano is characteristic of Latin America and the Caribbean, particularly Chile, where it is a very rare male name, and Peru. Very seldom, William Maximiliano is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| William Maximiliano | Ecuador, Chile, Peru, Argentina |