| IllÉS | | - | Hungarian | |
| Ilona | | EE-lo-naw (Hungarian), ee-LO-nah (German), EE-lo-nah (Finnish) | Hungarian, German, Finnish, Latvian, Lithuanian, Polish, Czech | |
| Ilonka | | EE-lon-kaw | Hungarian | |
| Imre | | EEM-re | Hungarian | |
| Imrus | | - | Hungarian | |
| Inga | | ING-ah (Swedish), ING-gah (German), EEN-gah (Russian) | Swedish, Danish, Norwegian, Icelandic, Latvian, Lithuanian, German, Russian, Ancient Scandinavian, A | |
| Ioannu | | - | Old Church Slavic | |
| Iosifu | | - | Old Church Slavic | |
| IrÉN | | - | Hungarian | |
| Irena | | ee-RE-nah (Polish), ee-RAY-nah (Dutch) | Polish, Czech, Slovene, Croatian, Serbian, Dutch, Lithuanian | |
| Irma | | EER-mah (German, Finnish), UR-mə (English) | German, English, Dutch, Finnish, Spanish, Italian, Georgian, Lithuanian, Hungarian (Rare), Ancient G | |
| Irmuska | | EER-moosh-kaw | Hungarian (Rare) | |
| Isaaku | | - | Old Church Slavic | |
| Iseult | | i-SOOLT (English), i-ZOOLT (English), EE-səlt (English) | Arthurian Romance | |
| Ismail | | - | Arabic, Uyghur | |