- Kaderlik
- Kadrmas
- Kahn
- Kalisky
- Kallinen
- Kamdar
- Kaminski
- Kandell
- Kang
- Kangas
- Kaplan
- Karnesky
- Kaspar
- Kastelic
- Kaszycki
- Kater
- Katsura
- Kattner
- Kauble
- Kaufman
- Kayl
- Kays
- Keeler
- Keep
- Keepers
- Kehoe
- Keizer
- Kelly
- Kemler
- Kemp
- Kempf
- Kennedy
- Kent
- Kenton
- Keppers
- Kerner
- Kerns
- Kernutt
- Kerr
- Kershner
- Kesey
- Kidd
- Kifer
- Killgore
- Kim
- Kimball
- Kimble
- Kimmel
- Kincaid
- King
- Kingman
- Kingsley
- Kingzett
- Kinney
- Kinnish
- Kintz
- Kirchner
- Kirk
- Kirkpatrick
- Kirtley
- Kitterman
- Kittleson
- Kivett
- Klassert
- Kleger
- Klein
- Klohn
- Klopfer
- Kloster
- Kluth
- Knapp
- Knaus
- Knebel
- Knight
- Knoedler
- Knowlton
- Knudson
- Knuffke
- Koch
- Kochevar
- Kocjan
- Kodama
- Koelling
- Koepp
- Koerner
- Koester
- Kohler
- Kohn
- Kokensparger
- Kolb
- Kolp
- Konieczka
- Konrady
- Koors
- Kowalko
- Kramer
- Krause
- Krauss
- Kress
- Kristensen
- Kroeger
- Kronholm
- Kruit
- Krumdieck
- Kruysman
- Kubli
- Kugel
- Kuhl
- Kuhlman
- Kuhn
- Kulick
- Kutz