- Johnson (continued)
- Johnston
- Joiner
- Jolly
- Jones
- Jonkman
- Jordan
- Jorgensen
- Joseph
- Joslin
- Joslyn
- Jourdanais
- Joy
- Joyce
- Joyslin
- Judd
- Judge
- Judkins
- Juede
- Julian
- Jungman
- Justus
- Jzabel
- Kaba
- Kacher
- Kahler
- Kahn
- Kaine
- Kalee
- Kalvelage
- Kammeraad
- Kane
- Kaneen
- Kannady
- Kanous
- Kaple
- Karam
- Karich
- Karl
- Karlson
- Karns
- Karstens
- Karstensen
- Kartsounis
- Kasun
- Katial
- Kauffman
- Kaufman
- Kaven
- Kaviani
- Kay
- Kayanagi
- Kazanjian
- Kearl
- Kearney
- Kearns
- Keast
- Keating
- Keaveney
- Keefe
- Keele
- Keeler
- Keen
- Keenan
- Keene
- Keeney
- Keesecker
- Keet
- Kehm
- Kehoe
- Kehrer
- Keigher
- Keillor
- Keirnan
- Keith