| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| ITXARO | - | Basque | ||
| ITXASO | - | Basque | ||
| ITZAL | - | Basque | ||
| ITZEL | - | Native American, Mayan | ||
| ITZHAK | - | Hebrew | ||
| ITZIAR | - | Basque, Spanish | ||
| IUCUNDA | - | Late Roman | ||
| IUDAS | - | Biblical Latin | ||
| IUDICAEL | - | Ancient Celtic | ||
| IUDITH | - | Biblical Latin | ||
| IUDOCUS | - | Ancient Celtic (Latinized) | ||
| IULIA | YOO:-li-a (Ancient Roman) | Romanian, Ancient Roman | ||
| IULIAN | - | Romanian | ||
| IULIANA | - | Romanian, Ancient Roman | ||
| IULIANUS | - | Ancient Roman |