| Igor | | EE-gər (Russian), EE-gawr (Polish) | Russian, Polish, Slovene, Croatian, Serbian, Macedonian | |
| Ilija | | - | Macedonian, Serbian, Croatian, Bulgarian | |
| Ilinka | | - | Macedonian, Serbian, Croatian | |
| Ina | | EE-nə (English), IE-nə (English), EE-nah (Swedish, Dutch, Limburgish) | English, German, Swedish, Norwegian, Danish, Dutch, Limburgish, Croatian | |
| Ines | | - | Italian, Slovene, Croatian | |
| Irena | | ee-RE-nah (Polish), ee-RAY-nah (Dutch) | Polish, Czech, Slovene, Croatian, Serbian, Dutch, Lithuanian | |
| Iskra | | - | Bulgarian, Macedonian, Croatian, Serbian | |
| Iva (1) | | - | Bulgarian, Serbian, Croatian, Macedonian | |
| Ivan | | ee-VAHN (Russian, Ukrainian), IE-vən (English) | Russian, Bulgarian, Ukrainian, Belarusian, Serbian, Croatian, Czech, Slovak, Macedonian, Slovene, En | |
| IvanČIca | | - | Croatian | |
| Ivana | | - | Czech, Slovak, Serbian, Croatian, Slovene, Bulgarian, Macedonian | |
| Ivanka | | - | Bulgarian, Czech, Slovak, Serbian, Croatian, Slovene | |
| Ivica | | - | Croatian, Serbian | |
| Ivka | | - | Croatian, Bulgarian, Slovak, Czech | |
| Ivo (2) | | - | Bulgarian, Serbian, Croatian, Macedonian | |