| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Guglielmo | gool-LYEL-mo | Italian | ||
| Guido | GWEE-do (Italian), GEE-do (German) | Italian, German | ||
| Gustavo | goo-STAH-vo (Italian, Spanish) | Italian, Spanish, Portuguese | ||
| Iacopo | - | Italian | ||
| Ida | IE-də (English), EE-dah (German, Swedish, Danish, Dutch, Italian) | English, German, Swedish, Norwegian, Danish, Dutch, Italian, Spanish, Portuguese, Hungarian, Slovene | ||
| Ignazio | - | Italian | ||
| Ilaria | - | Italian | ||
| Ilario | - | Italian | ||
| Ilda | - | Italian | ||
| Ileana | - | Romanian, Spanish, Italian | ||
| Imelda | ee-MEL-dah | Italian, Spanish | ||
| Imma | - | Italian, Catalan | ||
| Immacolata | - | Italian | ||
| Ines | - | Italian, Slovene, Croatian | ||
| Innocenzo | - | Italian |