- K
- Kackley
- Kaegy
- Kagey
- Kahle
- Kahmer
- Kahn
- Kaiser
- Kaller
- Kamfer
- Kanagy
- Kane
- Kannay
- Kanney
- Kanouse
- Kaplinger
- Karicofe
- Karn
- Karnaey
- Karnes
- Karr
- Kaslow
- Kasper
- Katsorelos
- Katzen
- Kauffman
- Kaufman
- Kavanaugh
- Kaylor
- Keagy
- Keane
- Kearney
- Keckley
- Kee
- Keedeer
- Keefe
- Keeler
- Keeley
- Keene
- Keener
- Keens
- Keeran
- Keezel
- Keezell
- Keezle
- Kegley
- Keifer
- Keiffer
- Keim
- Keister
- Keiter
- Keith
- Keithly
- Kellar
- Keller
- Kelley
- Kellogg
- Kelly
- Kelpatrick
- Kemerer
- Kemp
- Kemper
- Kempton
- Ken
- Kendall
- Kendrick
- Kennedy
- Kennerly
- Kenney
- Kennon
- Kenny
- Kent
- Keovoravong
- Kephart
- Keplinger
- Kepner
- Keran
- Kerestesy
- Kerlin
- Kerline
- Kerling
- Kern
- Kerns
- Kerr
- Kersey
- Kersey-Clutteur
- Kersh
- Kerst
- Kesinger
- Kesiter
- Kesler
- Kesling
- Kesner
- Kessner
- Kesterson
- Kestner
- Ketterman
- Ketterson
- Kewin
- Key
- Keyes
- Keys
- Keysaer
- Keysear
- Keyser
- Keyton
- Khatman
- Khochareun
- Kibler
- Kiblinger
- Kice
- Kicklighter
- Kidd
- Kieffer
- KIein
- Kiger
- Kilburn
- Kilby
- Kile
- Kilimnik
- Kille
- Killen
- Killian
- Kilpatrick
- Kimata
- Kimble
- Kimbough
- Kimmell
- Kincaid
- Kincheloe
- Kindel
- King
- Kingan
- Kingrea
- Kingree
- Kingsley-Ibeh
- Kingston
- Kinhead
- Kinkade
- Kinkead
- Kinney
- Kiplinger
- Kipps
- Kips
- Kiracofe
- Kirby
- Kirichun
- Kirilyuk
- Kirk
- Kirkland
- Kirkley
- Kirkpatrick
- Kirtley
- Kisamore
- Kiser
- Kisling
- Kissinger
- Kite
- Kite-Taylor
- Kittle
- Kittrell
- Kivitt
- Klein
- Kline
- Kling
- Klingel
- Klinger
- Klingstein
- Kloscak
- Kluge
- Knapp
- Kneedler
- Kneiple
- Kneipler
- Kniceley
- Knicely
- Knick
- Knickley
- Knicley
- Kniebusch
- Knight
- Knighten
- Knighting
- Knighton
- Knipe
- Knipple
- Knisely
- Knisley
- Kniss
- Knootz
- Knopp
- Knott
- Knotts
- Knowles
- Knupp
- Knuss
- Koch
- Kohlwey
- Kohne
- Kontz
- Konzman
- Koogler
- Koontz
- Koudelka
- Kovach
- Kovalyuk
- Kowalski
- Kraft
- Kramer
- Kratz
- Kratzer
- Kraus
- Kraybill
- Krech
- Kreider
- Krickenberger
- Krider
- Krim
- Kring
- Kronk
- Kropp
- Krotzer
- Krouse
- Krupp
- Kudrick
- Kuester
- Kuhns
- Kulp
- Kunitsa
- Kunz
- Kurkewicz
- Kurtz
- Kuster
- Kuykendal
- Kuykendall
- Kyger
- Kyle