- Laatsch
- Labate
- Labay
- Labbe
- Labin
- Labuda
- Labut
- Lacic
- Lacoe
- Laconi
- Ladich
- Ladow
- Ladwig
- Laidig
- Lake
- Lakic
- Lamb
- Lambert
- Lammers
- Lamont
- Lampe
- Lamphier
- Lampkin
- Lampner
- Lancaster
- Lance
- Lancianese
- Landis
- Landon
- Landrum
- Lane
- Laney
- Lange
- Langenfeld
- Langrell
- Langston
- Langton
- Lanik
- Laning
- Laramore
- Largent
- Larimore
- Larose
- Larsen
- Larson
- Lartent
- Lasalle
- Lash
- Laslo
- Latchic
- Lathan
- Latson
- Latta
- Lauck
- Lauderdale
- Lauer
- Laurenti
- Lauro
- Lavery
- Lavictoire
- Laviers
- Lawrence
- Lawson
- Lay
- Laybourne
- Lazoran
- Lazos
- Lazzerini
- Lea
- Leach
- Leading
- Leas
- Leasure
- Lebarre
- Lebold
- Lederman
- Ledford
- Ledgerwood
- Lee
- Leeson
- Leffler
- Leforge
- Legg
- Legrand
- Lehman
- Leibowitz
- Leidy
- Leigh
- Leipold
- Lekic
- Lemasters
- Lemke
- Lemley
- Lemmon
- Lemon
- Lenarduzzi
- Lengyel
- Lenihan
- Lenke
- Lentz
- Lenz
- Leonard
- Leonhard
- Leonhardt
- Leonino
- Lepkowski
- Leporis
- Lerner
- Leslie
- Lesner
- Lessem
- Lester
- Lettieri
- Levan
- Levers
- Levey
- Levin
- Lewis
- Leyden
- Leyerle
- Libbers
- Lichtenberger
- Lieberman
- Lieberth
- Liese
- Lieving
- Liggens
- Light
- Ligon
- Liles
- Lilley
- Lilly
- Lincicome
- Lincoln
- Lindas
- Lindberg
- Lindenberger
- Linder
- Lindesmith
- Lindsey
- Lindstrom
- Lines
- Lionetti
- Lipari
- Lipscomb
- Litman
- Little
- Litton
- Livadas
- Livengood
- Livers
- Livigni
- Llewellyn
- Lloyd
- Lobalzo
- Locascio
- Locastro
- Lockett
- Lockhart
- Lockshin
- Lofgren
- Loftus
- Logan
- Lollar
- Lomax
- Lombardi
- Long
- Longfellow
- Longworth
- Lonsdale
- Loomis
- Lorentzen
- Lorson
- Lough
- Louis
- Love
- Lovelace
- Lovell
- Lovett
- Lowe
- Lowrey
- Lowry
- Lowther
- Lucas
- Lucore
- Ludwig
- Lueptow
- Luke
- Lukotch
- Luman
- Lupinetti
- Luplow
- Lute
- Lutz
- Lux
- Luxmore
- Lyden
- Lynch
- Lynum
- Lyons