- Lacamp
- Lachman
- Lacy
- Ladau
- Ladd
- Ladu
- Lake
- Lambright
- Land
- Landers
- Landon
- Landrum
- Landry
- Landsman
- Lane
- Langan
- Langdon
- Lange
- Langenberg
- Langhoff
- Lanini
- Lanning
- Lanz
- Lapeere
- Larsen
- Larson
- Lassen
- Latham
- Latimer
- Laursen
- Lavely
- Lawrence
- Laws
- Lawson
- Leach
- Leaf
- Leahy
- Leary
- Leckie
- Leckington
- Lecompte
- Lee
- Leerssen
- Lees
- Lefevre
- Leffler
- Lehman
- Leigh
- Leighter
- Leiman
- Lemire
- Lemmer
- Lemos
- Lesch
- Leslie
- Lester
- Lettkeman
- Leung
- Levine
- Levy
- Lewis
- Ley
- Li
- Liberty
- Lichtenstein
- Lichtenwalter
- Lidz
- Liening
- Light
- Lind
- Lindberg
- Linden
- Lindgren
- Lindly
- Lindstrom
- Linn
- Lipinsky
- Lipsett
- Littlejohn
- Livermore
- Lloyd
- Lobue
- Locken
- Lockman
- Lodestein
- Lodl
- Lofton
- Logan
- Loge
- Logue
- Lohr
- Loiler
- Long
- Longstreet
- Lonnquist
- Loomis
- Looney
- Loos
- Loose
- Lorch
- Lorimer
- Louderback
- Loughary
- Love
- Lovell
- Lower
- Lowery
- Lowry
- Lubahn
- Lucas
- Lueck
- Luger
- Lum
- Lunas
- Lund
- Lundeen
- Lundstrom
- Lunger
- Lutterman
- Lutz
- Luzzi
- Lyda
- Lydum
- Lyford
- Lyman
- Lynch