| Name | Meaning | Gender | Origin |
|---|
| Jayce | Moon | Male | English |
| Jayda | Green Gemstone | Unisex | English |
| Jitterbug | | Male | Hebrew |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joel | God is willing, Jehova is the Lord | Male | Hebrew |
| 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 |
| Jumbo | Unusually large person, animal or thing e.g. Jumbo Jet. From African 'jumba' meaning elephant. | Male | |
| Jurgen | German form of George
| Male | |
| Kahlan | after the character in Terry Goodkind's Sword of Truth novels | Unisex | |
| Kandy | Cutie
| Male | |
| Kari | curly hair | Male | Norse |
| Kawaii | | Unisex | |
| Kazak | | Male | Hebrew |
| Keifer | Barrelmaker Variation of Cooper. Surname.
| Male | |
| Ken | Male Barbie Doll. | Male | English |
| Kenji | after Michael Kenji Shinoda, from the band Linkin Park | Male | Japanese |
| Kentuky | | Male | |
| Keo | | Unisex | Hebrew |
| King | King's field. King is one of several titles occasionally used as given names.
| Male | English |
| Kingston | From the king's village or estate King's field. King is one of several titles occasionally used as given names.
| Male | English |
| Kitto | Greek and Latin, bearer of Christ | Male | Cornish |
| Koala | | Male | Hebrew |
| Kojak | | Male | Hebrew |
| Komen | | Unisex | |