- Kaczmarek
- Kainady
- Kalafut
- Kalra
- Kane
- Kanode
- Kaplan
- Karim
- Karkenny
- Karl
- Karnes
- Karpowich
- Kase
- Katz
- Kaufman
- Kay
- Kearney
- Kearns
- Keeley
- Keeling
- Keen
- Keeton
- Keffer
- Kegley
- Keiley
- Keister
- Keith
- Kelley
- Kelly
- Kelso
- Kemp
- Kemper
- Kempf
- Kendrick
- Kennedy
- Kennerly
- Kepley
- Kerfoot
- Kern
- Kershner
- Kesler
- Kessel
- Kessing
- Kessler
- Kester
- Keyser
- Khan
- Kibler
- Kidd
- Kidman
- Kidwell
- Kilburn
- Killinger
- Kim
- Kimak
- Kimberlin
- Kimble
- Kincaid
- Kincer
- King
- Kingery
- Kinsey
- Kirk
- Kirkpatrick
- Kirtley
- Kiser
- Kitchens
- Kittleson
- Kitts
- Klever
- Klick
- Kline
- Klingman
- Klotzer
- Knight
- Knighton
- Koger
- Koll
- Komosa
- Konrad
- Koogler
- Kopeloff
- Koperniak
- Kostek
- Kostura
- Krack
- Kraige
- Krantz
- Krause
- Kresge
- Krisch
- Kristoff
- Kronau
- Krueger
- Krupski
- Kuehn
- Kulp
- Kummer
- Kuvik
- Kwiatkowski
- Kwitny