| Isaure | | - | French | |
| Isbrand | | - | Ancient Germanic | |
| Iscah | | - | Biblical | |
| Iseabail | | - | Scottish | |
| Iseult | | i-SOOLT (English), i-ZOOLT (English), EE-səlt (English) | Arthurian Romance | |
| Ishbel | | - | Scottish | |
| Ishild | | - | Ancient Germanic (Hypothetical) | |
| Ishmael | | ISH-may-əl (English), ISH-mee-əl (English) | Biblical | |
| Ishmerai | | - | Biblical | |
| Ishvi | | - | Biblical | |
| Isi | | - | Native American, Choctaw | |
| Isidor | | EE-see-dawr (German) | German, Russian, Macedonian | |
| Isidora | | ee-see-DHO-rah (Spanish), ee-zee-DO-rah (Italian), iz-i-DAWR-ə (English) | Serbian, Macedonian, Spanish, Portuguese, Russian (Rare), Italian (Rare), English (Rare), Ancient Gr | |
| Isidore | | IZ-i-dawr (English), ee-zee-DOR (French) | English, French, Georgian, Jewish | |
| Isidoros | | - | Ancient Greek | |