- Jones (continued)
- Jonkman
- Jordan
- Jorgensen
- Joseph
- Joslin
- Joslyn
- Jourdanais
- Joy
- Joyce
- Joyes
- Joyne
- Joynes
- Joyslin
- Judd
- Judge
- Judkins
- Judson
- Juede
- Julian
- Jungferman
- Jungman
- Justi
- Justus
- Jzabel
- Kaba
- Kacher
- Kahler
- Kahn
- Kaine
- Kaiser
- Kalee
- Kalinowski
- Kalvelage
- Kammeraad
- Kane
- Kaneen
- Kannady
- Kanous
- Kaple
- Karam
- Karich
- Karl
- Karlson
- Karner
- Karns
- Karst
- Karstens
- Karstensen
- Kartsounis
- Kaske
- Kasun
- Katial