| Isaac | | IE-zək (English) | English, Jewish, Biblical, Biblical Latin | |
| Isaak | | ee-SAH-ahk (Russian) | Russian, German, Biblical Greek | |
| Isaiah | | ie-ZAY-ə (English), ie-ZIE-ə (English) | English, Jewish, Biblical | |
| Isaias | | - | Biblical | |
| Iscah | | - | Biblical | |
| Ishmael | | ISH-may-əl (English), ISH-mee-əl (English) | Biblical | |
| Ishmerai | | - | Biblical | |
| Ishvi | | - | Biblical | |
| Ismael | | - | Spanish, Biblical Greek | |
| Ismahel | | - | Biblical Latin | |
| Israel | | IZ-ray-əl (English), IZ-ree-əl (English) | Jewish, English, Biblical, Biblical Greek | |
| Israhel | | - | Biblical Latin | |
| Issachar | | IS-ə-kahr (English) | Biblical | |
| Itamar | | - | Hebrew, Biblical Hebrew | |
| Ithai | | i-THAY-ie (English) | Biblical | |