- Kachik
- Kallman
- Kamenov
- Kamper
- Kanipe
- Kanya
- Kapec
- Kaplan
- Karle
- Karpinia
- Katritzky
- Kearney
- Kearns
- Keaton
- Keen
- Keenan
- Keene
- Keesling
- Keith
- Kell
- Kellett
- Kelly
- Kendall
- Kennard
- Kennerson
- Kepner
- Kerkhoff
- Kiefer
- Kiker
- Kilby
- Kimberlin
- Kimura
- Kinchen
- King
- Kirby
- Kirkland
- Kirksey
- Kish
- Kjallberg
- Kley
- Klingman
- Klock
- Kloss
- Knaggs
- Knapik
- Knight
- Koehler
- Kohlhof
- Kollat
- Kollmeier
- Konop
- Kopman
- Kovacevic
- Koval
- Kowal
- Kozak
- Kozuma
- Kraemer
- Krank
- Krause
- Kravitz
- Kreeger
- Kreider
- Krigbaum
- Kroen
- Kroll
- Krueger
- Krynski
- Kubler
- Kuck
- Kumar
- Kurtz
- Kvaltine
- Kverneland