- Laa
- Laake
- Labar
- Labatt
- Labauve
- Labay
- Labeaux
- Labenz
- Labrague
- Lacause
- Lacayo
- Lachapelle
- Lacoste
- Lacour
- Ladd
- Ladwig
- Lafferty
- Lafield
- Lafuente
- Lagrone
- Laguna
- Lahtinen
- Lain
- Laird
- Lake
- Lakhani
- Laljer
- Laloge
- Lam
- Lamb
- Lambert
- Lamberth
- Lambrecht
- Lamkin
- Lammert
- Lammons
- Lamoureaux
- Lamoureux
- Lampe
- Lampert
- Lamphier
- Lamprea
- Lamy
- Lamza
- Lancaster
- Lanctot
- Land
- Landers
- Landez
- Landis
- Landon
- Landrum
- Landry
- Lane
- Lanford
- Lanfranco
- Langan
- Langdon
- Lange
- Langer
- Langford
- Langley
- Langlinais
- Langthorp
- Lanier
- Lank
- Lankford
- Lantrip
- Lantry
- Lanzafame
- Lanzen
- Laorange
- Lara
- Larcade
- Lareau
- Lares
- Large
- Larger
- Larios
- Laris
- Larme
- Laros
- Larralde
- Larrumbide
- Larsen
- Larson
- Larzelere
- Lasater
- Lascurain
- Lashbrook
- Lasho
- Laskowski
- Lassiter
- Last
- Latham
- Latimer
- Laubach
- Lauer
- Laughlin
- Laurence
- Lauver
- Laux
- Lavalle
- Lavalley
- Lavan
- Lavender
- Law
- Lawler
- Lawrence
- Lawson
- Laxson
- Lay
- Layer
- Layland
- Layman
- Laymon
- Layne
- Lazard
- Lazor
- Leach
- Leahy
- Leal
- Lebahn
- Leblanc
- Lebleu
- Leblond
- Lebouef
- Ledbetter
- Ledesma
- Leduc
- Ledwig
- Lee
- Leeper
- Leese
- Lefavour
- Leflore
- Legg
- Leggett
- Legler
- Legrand
- Lehman
- Lehnis
- Lehtinen
- Leibold
- Leidig
- Leifeste
- Leigh
- Leighton
- Leija
- Leininger
- Leiser
- Leistra
- Lelam
- Leland
- Lemaster
- Lemay
- Lemessurier
- Lemire
- Lemley
- Lemons
- Lempa
- Lenk
- Lenning
- Lennox
- Lentz
- Leon
- Leonard
- Leonhardt
- Leos
- Leosz
- Lerma
- Lesch
- Lesher
- Leslie
- Lester
- Lestz
- Leuschner
- Levels
- Levesque
- Levine
- Levy
- Lew
- Lewenthal
- Lewey
- Lewis
- Lezama
- Lezanic
- Libby
- Liberto
- Lichtenberg
- Lieck
- Lien
- Lifschultz
- Lightbourne
- Lim
- Limas
- Limon
- Lin
- Linares
- Lincoln
- Lindemood
- Lindholm
- Lindley
- Lindner
- Lindquist
- Lindsey
- Lineberry
- Linn
- Linson
- Linton
- Lipe
- Lipps
- Lipscomb
- Lira
- Liserio
- Lister
- Litofsky
- Little
- Littlefield
- Littles
- Littleton
- Littrell
- Liu
- Livingston
- Livingstone
- Lizcano
- Llamas
- Llano
- Lloyd
- Loader
- Loadman
- Locastro
- Locati
- Lochte
- Lock
- Lockamy
- Locke
- Lockett
- Lockhart
- Lockwood
- Lodde
- Loeffler
- Loera
- Lofland
- Logan
- Logeman
- Lohman
- London
- Londos
- Long
- Longoria
- Longway
- Looney
- Lopez
- Loranc
- Loranger
- Lord
- Loredo
- Lorenz
- Loring
- Losoya
- Lothrop
- Lott
- Loturco
- Loughlin
- Lounsbery
- Louy
- Lovall
- Lovato
- Love
- Lovelady
- Lovins
- Low
- Lowak
- Lowder
- Lowe
- Lowery
- Lowrance
- Lowrey
- Loza
- Lozano
- Lubbering
- Lubianski
- Lucas
- Luce
- Lucero
- Lucey
- Lucio
- Luckemeyer
- Luckhardt
- Luduena
- Ludwig
- Luera
- Luevano
- Lugo
- Luitin
- Lujan
- Luke
- Luker
- Lum
- Lumpkin
- Luna
- Lund
- Lundell
- Lundgren
- Lunz
- Lupiba
- Lupton
- Lusk
- Lussier
- Lusted
- Luster
- Luter
- Luther
- Lutz
- Luu
- Lybrook
- Lyle
- Lyles
- Lynch
- Lynn
- Lynum
- Lyon
- Lyons
- Lyssy