| Name | Meaning | Gender | Origin |
|---|
| Isabella | pledged to God | Female | Spanish |
| Isabelle | pledged to God | Female | |
| Isadora | gift of the moon | Female | Greek |
| Isha | one who protects | Female | English |
| Isis | throne | Female | Egyptian |
| Isolde | beautiful | Female | Welsh |
| Ivory | The hard, smooth, yellowish-white of an elephant's tusk. | Male | Word |
| Ivy | ivy plant, a wine | Female | Plant |
| Izzie | | Unisex | Hebrew |
| Izzy | Salvation By God | Male | English |
| Jack | after the Georgetown University mascot, Jack the Bulldog | Male | English |
| Jack | From John - God's gracious gift | Male | English |
| Jack Frost | | Unisex | Hebrew |
| Jackie | supplanter | Female | English |
| Jaeger | Hunter | Unisex | German |
| Jagger | a teamster | Male | English |
| James | From Jacob - To fill the place of another, supplanter. | Male | English |
| Jane | gracious, merciful, God is gracious | Female | English |
| Jasmine | Flower
| Female | Persian |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jax | God has been gracious: has shown favor. Based on John or Jacques.
| Male | Modern |
| Jazz | The romantic music
| Male | Word |
| Jazzy | Modern variant of Jasmine: combination of Jocelyn and the musical term jazz.
| Female | |