| Isaak | | ee-SAH-ahk (Russian) | Russian, German, Biblical Greek | |
| IsabÈL | | - | Occitan | |
| Isabel | | ee-sah-BEL (Spanish), IZ-ə-bel (English), ee-za-BEL (French), ee-zah-BEL (German) | Spanish, Portuguese, English, French, German | |
| Isabela | | ee-sah-BEL-ah (Spanish) | Spanish, Portuguese, Romanian | |
| Isabell | | ee-zah-BEL | German | |
| Isabella | | ee-zah-BEL-lah (Italian), iz-ə-BEL-ə (English) | Italian, German, English, Swedish, Norwegian, Danish, Dutch, Romanian | |
| Isabelle | | ee-za-BEL (French), IZ-ə-bel (English), ee-sah-BEL-lə (Dutch) | French, English, German, Dutch | |
| Isaia | | - | Italian | |
| Isaija | | - | Serbian, Macedonian | |
| Isak | | EE-sahk | Swedish, Norwegian, Danish | |
| Isamu | | ee-sah-moo | Japanese | |
| Isaura | | ee-SOW-rah (Spanish) | Portuguese, Spanish, Late Roman | |
| Isaurus | | - | Late Roman | |
| Isay | | - | Russian | |
| Isbrand | | - | Ancient Germanic | |