| Name | Meaning | Gender | Origin |
|---|
| J.R. | after the TV character in Dallas | Unisex | |
| Jack | after the Georgetown University mascot, Jack the Bulldog | Male | English |
| Jack | From John - God's gracious gift | Male | English |
| Jackie | supplanter | Female | English |
| James | From Jacob - To fill the place of another, supplanter. | Male | English |
| Jamie | Feminine of James | Female | Scottish |
| Janet | Variant of Jane | Female | English |
| Jason | the Lord is salvation | Male | Hebrew |
| Javier | Born in January
| Male | Spanish |
| Jayson | Healer. Alternate spelling of Jason.
| Male | |
| Jean-Claude | | Unisex | Hebrew |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jeremy | God will uplift, appointed by God | Male | English |
| Jesse | wealthy | Male | Hebrew |
| Jessica | God's grace | Female | Hebrew |
| Jessie | wealthy | Female | Anglicized |
| Jim | supplanter | Male | English |
| John | God is merciful | Male | Hebrew |
| Jonathan | God gives | Male | Hebrew |
| Joseph | God will increase | Male | Hebrew |
| Josephine | God will increase | Female | |
| Julie | Youthful: Jove's child. A feminine of Julian.
| Female | |
| Kane | tribute, warrior; the doubly-accomplished, golden; man, the eastern sky; beautiful | Male | Celtic |
| Katarina | pure | Female | Czech |