L
- Laddville, California – Alphonso Ladd (founder)
- La Fayette, Alabama and La Fayette, Illinois – Gilbert du Motier, marquis de Lafayette
- LaFayette/Lafayette – Gilbert du Motier, marquis de Lafayette, 14 places in
- California – Georgia – Indiana – Kentucky – Louisiana – Minnesota – New York – Allen County, Ohio – Madison County, Ohio – Oregon – Tennessee – Chippewa County, Wisconsin – Monroe County, Wisconsin – Walworth County, Wisconsin
- Lafayette, Colorado – Lafayette Miller (settler and husband of Mary Miller, who platted the town)
- Lafayette County, Florida – Gilbert du Motier, marquis de Lafayette
- Lafayette Township – Gilbert du Motier, marquis de Lafayette, 16 places in
- Coles County, Illinois – Ogle County, Illinois – Allen County, Indiana – Floyd County, Indiana – Madison County, Indiana – Owen County, Indiana – Allamakee County, Iowa – Bremer County, Iowa – Story County, Iowa – Chautauqua County, Kansas – Michigan – Minnesota – New Jersey – Coshocton County, Ohio – Medina County, Ohio – Pennsylvania
- Lairds Landing, California – George and Charles Laird (early settlers)
- Lake Charles, Louisiana – Charles Sallier
- Lake Wilson, Minnesota – Jonathan E. Wilson (landowner)
- Lamoine, Maine – DeLamoine (early landowner)
- Lanare, California – L.A. Nares (developer)
- Land, California – A.H. Land (local lumber company president)
- Landaff, New Hampshire – Bishop of Llandaff (Llandaff is the spelling of the name on the town charter)
- Lanesborough, Massachusetts – Countess of Lanesborough
- Langdon, New Hampshire – Governor John Langdon
- Laramie, Wyoming – Jacques La Ramée (French-Canadian fur trader)
- Largo, California – Lemuel F. Long (early settler; Largo is Spanish for Long)
- Larkin's Landing, California – Stephen Larkin (early settler)
- Latrobe, California and Latrobe, Pennsylvania – Benjamin Henry Latrobe, II
- Laughlin, California – James H. Laughlin, Jr. (landowner)
- Laughlin, Nevada – Don Laughlin (founder)
- Lavers' Crossing, California – David Lavers (founder)
- Lawrence, Massachusetts – Abbott Lawrence (founder)
- Laytonville, California – F.B. Layton (founder)
- Le Grand, California – William Legrand Dickinson
- Le Mars, Iowa – Lucy Underhill, Elizabeth Parson, Mary Weare, Anna Blair, Rebecca Smith and Sarah Reynolds (the first initials of six women aboard on a railroad excursion)
- Leavitt, California – May F. Leavitt (first postmaster)
- Lebec, California – Peter Lebecque or Lebeck (killed by a bear nearby in 1837)
- Lee, California – Dick Lee (discoverer of gold at the site)
- Lee, Maine – Stephen Lee (settler)
- Lee, Massachusetts and Lee, New Hampshire – General Charles Lee
- Lee County, Florida – Confederate General Robert E. Lee
- Lee Vining, California – Leroy Vining (founder)
- Leesville, California – Lee Harl (local landowner)
- Lemoore, California – Dr. Lovern Lee Moore (early settler)
- Lempster, New Hampshire – from one of the titles of Sir Thomas Farmer of a "Lempster" in England
- Lennox, South Dakota – Ben Lennox (railroad official)
- Letcher, California – F.F. Letcher (county supervisor)
- Leverett, Massachusetts – John Leverett (twentieth governor of the Massachusetts Bay Colony)
- Levittown, 2 places in New York/Pennsylvania &ndash William Levitt
- Lewis, Vermont – Nathan, Sevignior and Timothy Lewis (landholders)
- Lewiston, Minnesota – Johnathan Smith Lewis (settler)
- Lewistown, Pennsylvania – William Lewis
- Lila C, California – Lila C. Coleman (mine owner's daughter)
- Lillis, California – Simon C. Lillis (ranch superintendent)
- Limon, Colorado – John Limon (or Lymon) (railroad construction supervisor)
- Lincoln, Alabama and Lincoln, Vermont – Major General Benjamin Lincoln
- Lincoln, California – Charles Lincoln Wilson (one of the organizers and directors of the California Central Railroad)
- Lincoln, Illinois, Lincoln, Nebraska and Lincoln, Rhode Island – Abraham Lincoln
- Lincoln, Maine – Enoch Lincoln (Maine's sixth governor)
- Lincoln, New Hampshire – Henry Fiennes Pelham-Clinton, 2nd Duke of Newcastle, 9th Earl of Lincoln
- Lincoln Center, Kansas – Abraham Lincoln (indirectly, via Lincoln County, Kansas)
- Lincolnville, Maine – Major General Benjamin Lincoln (landowner)
- Lippitt, California – Col. Francis J. Lippitt (founder)
- Litchfield, California – Thomas Litch (pioneer)
- Litchfield, New Hampshire – George Henry Lee, Earl of Litchfield
- Livermore, California – Robert Livermore
- Livermore, Maine – Deacon Elijah Livermore (early settler)
- Livermore Falls, Maine – Deacon Elijah Livermore (early settler)
- Livingston, California – Charles C. Livingston (railroad official)
- Livingston, Montana – Johnston Livingston (Northern Pacific Railway stockholder and director)
- Livingston, New Jersey – William Livingston
- Lockwood, 3 places in California/New York/West Virginia – Belva Ann Lockwood
- Logan, Montana – Captain William Logan (died in the Battle of the Big Hole)
- Longmont, Colorado – Stephen Harriman Long (explorer) (indirectly, via Longs Peak)
- Longville, California – W.B. Long (early hotel and saw mill owner)
- Loomis, California – Jim Loomis (railroad agent, postmaster)
- Lorenzo, Texas – Lorenzo Dow
- Los Angeles – Our Lady the Queen of the Angels
- Loudon, New Hampshire – John Campbell, 4th Earl of Loudoun (note spelling)
- Louisiana, Missouri – Louisiana Basye (daughter of local settlers)
- Louisville, Kentucky – Louis XVI of France
- Loveland, Colorado – William A.H. Loveland (president of the Colorado Central Railroad)
- Lovell, Maine – Captain John Lovewell (note spelling)
- Lovelock, California – George Lovelock (early merchant)
- Lowell, Massachusetts – Francis Cabot Lowell
- Lubbock, Texas – Thomas Saltus Lubbock
- Lucia, California – Lucia Dani (first postmaster)
- Lufkin, Texas – Abraham P. Lufkin (cotton merchant and Galveston city councilman)
- Lundy, California – W.J. Lundy (sawmill owner)
- Lunenburg, Massachusetts – from one of the titles of King George II of Great Britain, Duke of Brunswick-Lüneburg
- Lunenburg, Vermont – from one of the titles for Prince Karl Wilhelm Ferdinand of Brunswick-Lunenburg
- Lusk, Wyoming – Frank S. Lusk (rancher and Wyoming Central Railway stockholder)
- Lutherville, Maryland – Martin Luther (16th century German reformer)
- Lyman, Maine – Theodore Lyman (merchant)
- Lyman, New Hampshire – General Phineas Lyman (commander in the French and Indian War)
- Lyndeborough, New Hampshire – Benjamin Lynde (Chief Justice of Massachusetts after town was named)
- Lyndon, Vermont – Josias Lyndon (governor of Rhode Island)
- Lyons, Colorado – Edward S. Lyon (founder)
- Lysander, New York – Lysander (Spartan military leader)
Read more about this topic: List Of American Places Named After People