Lancelot
Germanic: land
(Lance, Launce)

Lane
Middle English: the narrow road
(Laney, Lain, Laine)

Lars
Latin: laurel

Laurence
Latin: laurel or bay tree
(Lars, Lauren, Laurie, Lawrence, Loren, Lorcan, Laurens, Lawrie, Laurent, Laurenz, Lauritz)

Lee
Old English: the meadow
(Leigh)

Leif
Scandinavian: beloved
(Lief)

Leonard
Germanic: bold lion
(Leo, Leon, Leonhart, Leonid, Lionel, Lyon, Lyonel)

Leroy
Old French: the king
(LeRoi)

Lesley
Old English: man from the low-lying meadow
(Lee, Leigh, Les, Leslie, Lezlie)

Lindsey
Old English: of the linden tree
(Lindy, Lindsay, Linsey)

Linus
Latin: flaxen-colored

Llewellyn
Welsh: like a lion, or lightning
(Lew, Lewis, Llywellyn, Lyn, Lynn)

Lloyd
Welsh: gray
(Floyd)

Lewis
Old German: glorious in battle, or famous warrior
(Aloysius, Lew, Lewis, Lou, Louie, Ludwig, Luis)

Lucian
Latin: man of light
(Luc, Luciano, Lucien)

Luke
Greek: someone from Lucania
Latin: luminous
(Lucais, Lukas)

Lyle
French: the island
(Lisle, Ly, Lyell)

Lyn
Old English: brook
(Lin, Linn, Lynn)

Lynley
Old English: the meadow near the brook