| Name | Meaning | Gender | Origin |
|---|
| Jerry | after Jerry Garcia, The Grateful Dead | Male | English |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jimmy | supplanter | Male | English |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joe | Abbreviation of Joseph.
| Male | English |
| Joey | Abbreviation of Joseph.
| Male | |
| Joey | Abbreviation of Joseph.
| Male | |
| John | God is merciful | Male | Hebrew |
| Johnny | the Lord is gracious | Male | English |
| Jon | God is gracious; or gift of Jehovah | Male | English |
| Joseph | God will increase | Male | Hebrew |
| Judas | praised | Male | Greek |
| Julian | Jove's child. Form of Julius and family clan name of several powerful Roman emperors. Biblical Roman centurion Julius saved Paul's life during a hazardous voyage
| Male | English |
| Jupiter | Zeus, Father | Male | Roman |
| Kevin | handsome | Male | Irish |
| Kim | chief | Male | English |
| Laertes | from Shakespeare's Hamlet | Unisex | |
| Lance | knight's attendant; land | Male | English |
| Lancelot | Knight of Arthur and lover of Guinevere
| Male | |
| Launcelot | Knight of Arthur and lover of Guinevere
| Male | |
| Lazar | God Is My Helper | Unisex | Hungarian |
| Leaf | | Male | |
| Lennox | amid the lems, from the field of elm trees | Male | Scottish |
| Leo | Lion.
| Male | Latin |
| Leonardo | Lion-bold. Leonardo da Vinci is considered by many to be the most brilliant and creative men who ever lived.
| Male | Italian |