- Laabs
- Labbe
- Labere
- Lacey
- Lacy
- Lafay
- Lafond
- Lafrenz
- Lagoon
- Lai
- Laidlaw
- Laing
- Lake
- Laky
- Lallatin
- Lalley
- Lamansky
- Lamarche
- Lamb
- Lamberson
- Lambert
- Lambuth
- Lamke
- Lamont
- Lamontagne
- Lamprecht
- Lance
- Land
- Landavazo
- Landin
- Landon
- Landreth
- Lane
- Lanfear
- Lang
- Langford
- Langworthy
- Lanier
- Lanning
- Lansbery
- Lanza
- Laporte
- Lappens
- Larabee
- Largent
- Laritz
- Larkin
- Larrinaga
- Larsen
- Larson
- Lasalle
- Lata
- Latham
- Latreille
- Latta
- Laufenburger
- Laughlin
- Laughrin
- Laursen
- Lauterbach
- Lavoie
- Law
- Lawless
- Lawrnece
- Lawson
- Layer
- Leach
- Leahy
- Learned
- Leatham
- Leavitt
- Lechtenberg
- Ledbetter
- Ledgard
- Lee
- Leek
- Lefevre
- Leggate
- Leggett
- Lehn
- Lehrman
- Leigh
- Leighton
- Leinen
- Leister
- Lekan
- Lemke
- Lemna
- Lenon
- Lenz
- Lenzi
- Leonard
- Lessor
- Lester
- Levanger
- Levitch
- Lewer
- Lewin
- Lewis
- Libby
- Lidstrom
- Lienkaemper
- Liethen
- Lile
- Lilly
- Linane
- Lincoln
- Lind
- Lindberg
- Lindeen
- Lindgren
- Lindholm
- Lindley
- Lindsey
- Lineberry
- Lininger
- Link
- Liston
- Littau
- Little
- Littman
- Littrell
- Livesay
- Lloyd
- Lobban
- Lockett
- Lockhart
- Locklear
- Lodge
- Lodman
- Loe
- Loftus
- Logan
- Lokken
- Long
- Longbottom
- Longeteig
- Longmuir
- Longstroth
- Loomis
- Looper
- Lopez
- Lord
- Lords
- Lorensen
- Lorimor
- Losasso
- Loseke
- Lostra
- Louangketh
- Loucks
- Loughmiller
- Loughrey
- Louie
- Lounsbury
- Louther
- Loutzenheiser
- Love
- Lovejoy
- Lovelace
- Loveless
- Lovely
- Lowe
- Lowry
- Lucas
- Ludders
- Ludeman
- Luft
- Lui
- Luke
- Luken
- Luker
- Lukes
- Lukesh
- Lumadue
- Lumenello
- Lund
- Lundquist
- Lungren
- Lunt
- Luscombe
- Lute
- Luthy
- Luttmann
- Luttrell
- Luvaas
- Lyda
- Lydon
- Lynch
- Lynn
- Lynskey
- Lyons
- Lysinger
- Lysne
- Lythgoe