| Name | Meaning | Gender | Origin |
|---|
| Jolie | French for pretty | Female | |
| Judy | Hebrew, He will be praised, woman from Judea | Female | English |
| Juliet | youthful | Female | English |
| Kaiser | Any of the emperors of The Holy Roman Empire, Austria or Germany | Unisex | |
| Katherine | Pure. Used since third century A.D. Early Latin forms Katerina and Caterina became Katharine and Catherine. French Cateline and English Catlyn came into wider use during medieval period when variants multiplied.
| Female | Greek |
| Katrina | Greek, pure | Female | |
| Kennedy | misshapen head | Female | Irish |
| Keno | | Unisex | Hebrew |
| Laura | bay laurel | Female | Latin |
| Lourdes | Reference to the Virgin Mary
| Female | Basque |
| Maddie | Of Magdala | Female | English |
| Magneto | Device that produces electricity. | Unisex | |
| Maia | nurse, mother, goddess of spring; great | Female | Greek |
| Manhattan | Whiskey | Unisex | |
| Mann | Hero | Unisex | English |
| Martian | | Unisex | Hebrew |
| Maui | | Unisex | |
| Maxx | Greatest | Unisex | English |
| Maya | Abbreviation of Amalia: variant of Maia.
| Female | Hebrew |
| Meg | Pearl | Female | English |
| Millicent | after the character in D.C. Simpson's online comic Ozy and Millie | Female | |
| Monger | | Unisex | Hebrew |
| Monroe | mouth of the Roe River; wheelwright | Female | Scottish |
| Monroe | mouth of the Roe River; wheelwright | Female | Scottish |
| Mystique | Air of mystery.
| Female | |