| Name | Meaning | Gender | Origin |
|---|
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jezebel | follower of idols | Female | Hebrew |
| Jiggs | | Unisex | Hebrew |
| Jim | supplanter | Male | English |
| Jimbo | Supplanter, Representative | Unisex | Hebrew |
| Jiminy | | Unisex | Hebrew |
| Jinxy | | Female | Hebrew |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joey | Abbreviation of Joseph.
| Male | |
| Joey | Abbreviation of Joseph.
| Male | |
| Johnny | the Lord is gracious | Male | English |
| Jonah | Dove. In the bible Jonah was on board a ship God caused to sink: sailors traditionally use the name Jonah to personify someone who brings bad luck.
| Male | Hebrew |
| Joplin | the afflicted | Male | English |
| Judy | Hebrew, He will be praised, woman from Judea | Female | English |
| Jujube | | Unisex | Hebrew |
| Juliette | youthful | Female | |
| Junior | Youthful person. Used to distinguish son from father where they have the same name | Male | Latin |
| Juniper | Juniper Tree | Female | English |
| Juno | queen of the heavens | Female | Latin |
| Jupiter | Zeus, Father | Male | Roman |
| Kala | time, black | Unisex | |
| Kanga | | Male | Hebrew |
| Karina | Italian, dear little one | Female | Scandinavian |