| Iga | | - | Polish | |
| Ignacja | | - | Polish | |
| Ignacy | | eeg-NAH-tsi | Polish | |
| Igor | | EE-gər (Russian), EE-gawr (Polish) | Russian, Polish, Slovene, Croatian, Serbian, Macedonian | |
| Ilona | | EE-lo-naw (Hungarian), ee-LO-nah (German), EE-lo-nah (Finnish) | Hungarian, German, Finnish, Latvian, Lithuanian, Polish, Czech | |
| Irena | | ee-RE-nah (Polish), ee-RAY-nah (Dutch) | Polish, Czech, Slovene, Croatian, Serbian, Dutch, Lithuanian | |
| Ireneusz | | ee-re-NE-uwsh | Polish | |
| Irenka | | ee-REN-kah (Polish) | Polish, Czech | |
| Iwan | | EE-wan (Welsh), EE-vahn (Polish) | Welsh, Polish | |
| Iwo | | EE-vaw | Polish | |
| Iwona | | ee-VAW-nah | Polish | |
| Iza | | - | Polish | |
| Izaak | | - | Polish | |
| Izabela | | ee-zah-BE-lah | Polish | |
| Izabella | | ee-zah-BEL-lah (Polish) | Hungarian, Polish | |