- Labenz
- Labinger
- Labinsky
- Laboda
- Labrache
- Labrash
- Lacasse
- Lachine
- Lackman
- Lackmann
- Lacorte
- Lacoste
- Lacroix
- Lacugna
- Ladas
- Lade
- Ladeburg
- Laden
- Ladenburg
- Ladniak
- Ladum
- Laemmle
- Lafferty
- Lafond
- Lafrance
- Lafranchi
- Lagarde
- Lagerquist
- Lagerwey
- Laguardia
- Lahti
- Lai
- Laigo
- Laing
- Lair
- Lakari
- Lake
- Lakew
- Lallaison
- Lam
- Lamar
- Lamarca
- Lamarre
- Lamb
- Lambert
- Lambright
- Lamers
- Lamotte
- Lampe
- Lamping
- Lamson
- Lancaster
- Lance
- Land
- Landa
- Lande
- Landeen
- Lander
- Landis
- Landress
- Landry
- Landy
- Lane
- Laney
- Lang
- Lange
- Langejones
- Langenwalter
- Langer
- Langford
- Langill
- Langland
- Langmann
- Langowski
- Langsen
- Langston
- Langton
- Langworthy
- Lannoye
- Lantz
- Lao
- Lapatinskas
- Lapaze
- Lapin
- Laplant
- Laporte
- Lapre
- Laquey
- Larican
- Laris
- Lariviere
- Larkin
- Larmer
- Larsen
- Larson
- Laschober
- Laslo
- Lassiter
- Lastomirsky
- Latham
- Lathan
- Lathrop
- Latourell
- Latta
- Lau
- Laube
- Laudan
- Lauder
- Lauderback
- Lauer
- Laufmann
- Laughlin
- Launderville
- Laurance
- Laurence
- Laurion
- Lauris
- Laush
- Lauthner
- Lavacot
- Lavaris
- Lavassar
- Lavelle
- Lavenia
- Laville
- Lavrinec
- Law
- Lawarree
- Lawless
- Lawrence
- Lawson
- Lawton
- Laxdall
- Laxson
- Layman
- Lazarou
- Lazerwitz
- Lazo
- Le
- Lea
- Leach
- Leaders
- Leahy
- Leake
- Leal
- Leander
- Learned
- Leary
- Leask
- Leatherman
- Leavell
- Leaver
- Leavesley
- Leavitt
- Lebailly
- Lebel
- Lebens
- Lebenzon
- Lebert
- Leblanc
- Leblond
- Lebon
- Leckie
- Lecocq
- Leconte
- Leddy
- Ledingham
- Ledoux
- Ledray
- Leduc
- Lee
- Leeds
- Leenstra
- Lefevre
- Lefkoff
- Legge
- Legrand
- Legsdin
- Legters
- Lehman
- Lehmann
- Lehmans
- Lehnerz
- Lei
- Leibert
- Leibold
- Leibrandt
- Leibst
- Leichter
- Leigh
- Leighton
- Leimback
- Leininger
- Leitch
- Leite
- Leland
- Lemberg
- Lembo
- Lemire
- Lemke
- Lemma
- Lemoine
- Lemon
- Lempriere
- Lemus
- Lenker
- Lennon
- Lentgis
- Lentz
- Lenz
- Leon
- Leonard
- Leong
- Leonhardi
- Leopold
- Lepley
- Leppa
- Lepse
- Leroy
- Lesh
- Leslie
- Lesperance
- Lester
- Lethin
- Letourneau
- Lettenmaier
- Letzing
- Leung
- Lev
- Levan
- Levasseur
- Leverty
- Levesque
- Leveugle
- Levey
- Levi
- Levin
- Levine
- Levitt
- Levy
- Lew
- Lewarch
- Lewellen
- Lewin
- Lewinsohn
- Lewis
- Lewy
- Lezon
- Li
- Lia
- Liang
- Liatos
- Liau
- Libby
- Lichtenstadter
- Lichtenstein
- Lichtman
- Lickey
- Licup
- Liddell
- Lidell
- Lidgard
- Lidstrom
- Liebel
- Lieber
- Lieberman
- Liebermann
- Liebert
- Lien
- Liffring
- Liftin
- Lightfoot
- Lih
- Liles
- Liljenberg
- Liljequist
- Lillibridge
- Lillieberg
- Lillington
- Lim
- Limacher
- Limbach
- Limmer
- Lin
- Linafelter
- Linardic
- Lincecum
- Lind
- Lindahl
- Lindberg
- Lindbergh
- Linde
- Lindell
- Lindeman
- Lindenburg
- Linder
- Lindholm
- Lindner
- Lindow
- Lindquist
- Lindsay
- Lindseth
- Lindskog
- Lindsley
- Lindstrom
- Linehan
- Linenberger
- Ling
- Lininger
- Link
- Linker
- Linkous
- Linn
- Lins-Morstadt
- Linson
- Lioe
- Lion
- Lipkin
- Lipnick
- Lippe
- Lippert
- Lippmann
- Liston
- Litch
- Litourneau
- Little
- Litton
- Litz
- Litzie
- Liu
- Livak
- Livingston
- Livingstone
- Llera
- Lloyd
- Lo
- Lobaugh
- Locatell
- Lock
- Locke
- Lockeman
- Lockerbie
- Lockhart
- Lockwood
- Lodge
- Loeb
- Loebach
- Loebel
- Loeffler
- Loesch
- Lofgren
- Lofstrom
- Lofthus
- Logan
- Lohnes
- Lohr
- Lohse
- Loisel
- Loken
- Loklingholm
- Lombard
- Lombardini
- London
- Loney
- Long
- Longanecker
- Longman
- Longmate
- Longton
- Lonsdale
- Loo
- Loodus
- Look
- Loomis
- Loop
- Loos
- Lopez
- Lopresti
- Lord
- Lorensen
- Lorenson
- Lorentzen
- Lorenz
- Lorenzana
- Lorenzen
- Lorenzo
- Lorge
- Lorimor
- Loring
- Lorrain
- Lorton
- Lorvick
- Losh
- Losk
- Loubet
- Loudon
- Lough
- Loughead
- Loughlin
- Loughridge
- Louie
- Louvier
- Lovaglio
- Love
- Lovejoy
- Loveland
- Loveless
- Lovell
- Lovering
- Lovett
- Lovinger
- Lovre
- Lovseth
- Low
- Lowe
- Lowen
- Lowenberg
- Lower
- Lowery
- Lowry
- Lowthian
- Lozano
- Lu
- Luber
- Lubin
- Lubke
- Lubow
- Luby
- Lucarelli
- Lucas
- Luce
- Luchino
- Luchnik
- Lucht
- Lucian
- Lucurell
- Ludolff
- Ludwig
- Luederitz
- Luetjen
- Luginina
- Lui
- Luiten
- Lukaszek
- Luke
- Lukens
- Luker
- Lulu
- Lum
- Lumley
- Luna
- Lunbom
- Lund
- Lundberg
- Lunde
- Lundgren
- Lundin
- Lundquist
- Lundstrom
- Lundwall
- Lunning
- Lunsford
- Luong
- Lusis
- Lusk
- Lutgen
- Luth
- Luther
- Lutton
- Luu
- Luukkonen
- Lux
- Luyombya
- Ly
- Lybecker
- Lycette
- Lydon
- Lygren
- Lyle
- Lynch
- Lyon
- Lyons
- Lysaker
- Lyshol