| Name | Meaning | Gender | Origin |
|---|
| Ink | | Unisex | |
| J.R. | after the TV character in Dallas | Unisex | |
| Jack Sloper | | Unisex | |
| Jacquelin | French form of Jacob
| Male | |
| James Potter | Harry's father who was killed by Lord Voldemort.
| Male | |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Javan | Son of Japtheth
| Male | Hebrew |
| Javiero | Born in January
| Male | |
| Jay | jaybird | Male | Latin |
| Jeeves | | Male | Hebrew |
| Jelly | | Unisex | Hebrew |
| Jerold | Variant of Gerald Rules by the spear.
| Male | |
| Joaquin | Abbreviation of the Hebrew name Jehoichin meaning Jehovah has established. Joaquin Miller the colorful 19th century poet-adventurer of the American west.
| Male | Spanish |
| 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 |
| Jore | God will uplift
| Male | |
| Joshua | God is salvation
| Male | Hebrew |
| Jules | youthful; soft, downy | Male | |
| Junior | Youthful person. Used to distinguish son from father where they have the same name | Male | Latin |
| Kactus | | Male | Hebrew |
| Kafir | | Male | Hebrew |
| Keene | Ancient.
| Male | |
| Keets | | Male | Hebrew |
| Keypie | | Unisex | |