| Island's name | Island group(s) | Country/Countries |
| Lae Atoll | Ralik Chain | Marshall Islands |
| Læsø | Kattegat | Denmark |
| Lady's Holm | Shetland Islands | Scotland |
| Lahesaar | Gulf of Finland | Estonia |
| Laidu | Küdema Bay, Baltic Sea | Estonia |
| Laika | Shepherd Islands | Vanuatu |
| Lakshadweep | Lakshadweep Islands | India |
| Isle La Motte | Lake Champlain, Vermont | United States |
| Lamb Holm | The South Isles, Orkney Islands | Scotland |
| Lamba | Shetland Islands | Scotland |
| Lambasaar | Pärnu Bay, Gulf of Riga | Estonia |
| Lambay | | Ireland |
| Lamma | Islands District, Hong Kong | China |
| Lampedusa | Pelagian Islands | Italy |
| Lampione | Pelagian Islands | Italy |
| Lamu | Lamu Islands | Kenya |
| Lanai | Hawaiian Islands, Hawaii | United States |
| Lanaux | Bastian Bay, Louisiana | United States |
| Langeland | | Denmark |
| Langenwerder | | Germany |
| Langeoog | East Frisian Islands | Germany |
| Langkawi | Kedah | Malaysia |
| Langli | North Frisian Islands | Denmark |
| Langor | Arno Atoll | Marshall Islands |
| Langøya | Vesterålen | Norway |
| Lankiam Cay | Spratly Islands | Disputed between: China,
Republic of China,
Vietnam,
Brunei,
Philippines, and
Malaysia |
| Lantau | Pearl River, Hong Kong | China |
| Lanz | Scott Islands, British Columbia | Canada |
| Lanzarote | Canary Islands | Spain |
| Larak | Persian Gulf | Iran |
| Lasqueti | Gulf Islands, British Columbia | Canada |
| Lastovo | | Croatia |
| Lau | Admiralty Islands | Papua New Guinea |
| Laughery | Ohio River, Kentucky | United States |
| Lauley | Gloucester Pool Ontario | Canada |
| Laurie | South Orkney Islands | Claimed by: the United Kingdom as part of the Falkland Islands and by
Argentina |
| Laurisaar | Baltic Sea | Estonia |
| Lausma | Baltic Sea | Estonia |
| Lavan | Persian Gulf | Iran |
| Lavezzi | Corsica | France |
| Lazaretto | Ionian Islands | Greece |
| Lebre | Alentejo islands | Portugal |
| Lefkada | Ionian Islands | Greece |
| Leftus | Lower Lough Erne | Ireland |
| Leipsoi | Dodecanese | Greece |
| Lélépa | Shepherd Islands | Vanuatu |
| Lemnos | North Aegean Islands | Greece |
| Lennox | Antártica Chilena Province | Chile |
| Leros | Dodecanese | Greece |
| Lesbos | North Aegean Islands | Greece |
| Lesser Mount Changtu | Zhoushan Archipelago | China |
| Lesser Mount Yang | Zhoushan Archipelago | China |
| Lesser Tunbs | Persian Gulf | Iran |
| Leung Shuen Wen | Hong Kong | China |
| Levanzo | Aegadian Islands | Italy |
| Levitha | Dodecanese Islands | Greece |
| Lewis | Thimble Islands, Connecticut | United States |
| Leyte | Visayas | Philippines |
| Lezíria Internacional | Alentejo islands | Portugal |
| Liancourt Rocks | | Administered by South Korea. Claimed by: Japan |
| Lib | Ralik Chain | Marshall Islands |
| Lidingö | Stockholm archipelago | Sweden |
| Lido | Venetian Lagoon | Italy |
| Lieutenant | Wellfleet Harbor, Cape Cod, Massachusetts | United States |
| Lihou | Channel Islands | Guernsey |
| Liialaid | Väinameri Sea | Estonia |
| Liisi laid | | Estonia |
| Liivakari | Gulf of Finland | Estonia |
| Likiep Atoll | Ratak Chain | Marshall Islands |
| Likoma | Lake Malawi | Malawi |
| Lindau | Lake Constance | Germany |
| Lindos | Dodecanese Islands | Greece |
| Linga Holm | The North Isles, Orkney Islands | Scotland |
| Linga near Muckle Roe | Shetland Islands | Scotland |
| Linga near Shetland Mainland | Shetland Islands | Scotland |
| Linga near Yell | Shetland Islands | Scotland |
| Linnusitamaa | Gulf of Riga | Estonia |
| Linosa | Pelagian Islands | Italy |
| Linua | Torres Islands | Vanuatu |
| Lipari | Aeolian Islands | Italy |
| Lismore | Inner Hebrides | Scotland |
| Lítla Dímun | Faroe Islands | Denmark |
| Little Andaman | Andaman Islands | India |
| Little Bear | Lake Winnipesaukee, New Hampshire | United States |
| Little Birch | Lake Winnipesaukee, New Hampshire | United States |
| Little Camp | Lake Winnipesaukee, New Hampshire | United States |
| Little Cayman | Cayman Islands | United Kingdom |
| Little Kitchener | Lake Huron, Ontario | Canada |
| Little Wellington Island | Aisén Region | Chile |
| Little Green | Hong Kong | China |
| Little Hurricane | Ohio River, Kentucky | United States |
| Little Mud | Louisiana | United States |
| Little Roe | Shetland Islands | Scotland |
| Little Sixmile | Lake Winnipesaukee, New Hampshire | United States |
| Little Skellig | Skellig Islands | Ireland |
| Little Wellington Island | Aisén Region | Chile |
| Liuheng | Zhoushan Archipelago | China |
| Lively | Falkland Islands | United Kingdom |
| Livingston | South Shetland Islands | Claimed by: Argentine Antarctica, Argentina,
Antártica Chilena Province of Chile, and
British Antarctic Territory of the United Kingdom |
| Livø | | Denmark |
| Lizard Island | Lizard Island Group | Australia |
| Ljusterö | Stockholm archipelago | Sweden |
| Llanddwyn | | Wales |
| Loaita | Spratly Islands | Disputed between: China,
Republic of China,
Vietnam,
Brunei,
Philippines, and
Malaysia |
| Lockes | Lake Winnipesaukee, New Hampshire | United States |
| Loh | Torres Islands | Vanuatu |
| Lokrum | | Croatia |
| Lolland | | Denmark |
| Lombo | Ribatejo islands | Portugal |
| Lombok | Lesser Sunda Islands | Indonesia |
| Lonely | Georgian Bay Ontario | Canada |
| Long | Tennessee River, Alabama and Tennessee | United States |
| Long | Alabama | United States |
| Long | New York | United States |
| Long | Bahamas | Bahamas |
| Long | Nova Scotia | Canada |
| Long | Hudson Bay, Nunavut | Canada |
| Long | Leeward Islands | Antigua and Barbuda |
| Long | Whitsunday Islands, Queensland | Australia |
| Long | New South Wales | Australia |
| Long | Gull Lake Ontario | Canada |
| Long | | Papua New Guinea |
| Long | Marlborough Sounds | New Zealand |
| Long | Fiordland | New Zealand |
| Long | Seychelles | Seychelles |
| Long | | Turkey |
| Long | Poole Harbour | United Kingdom |
| Long | Langstone Harbour | United Kingdom |
| Long | Mississippi River, Illinois | United States |
| Long | Boston Harbor, Massachusetts | United States |
| Long | Apostle Islands, Wisconsin | United States |
| Lookout | Georgian Bay Ontario | Canada |
| Loon | Lake Shetek, Minnesota | United States |
| Loon | Lake Winnipesaukee, New Hampshire | United States |
| Loon | Georgian Bay Ontario | Canada |
| Looney | Tennessee River, Tennessee | United States |
| Loosahatchie Bar | Mississippi River, Tennessee | United States |
| Lopez | San Juan Islands, Washington | United States |
| Lopud | Elafit Islands | Croatia |
| Lord Howe | Lord Howe Islands, New South Wales | Australia |
| Los Negros | Admiralty Islands | Papua New Guinea |
| Lošinj | | Croatia |
| Lõuna-Malusi | Malusi Islands, Gulf of Finland | Estonia |
| Low | South Shetland Islands | Claimed by: Argentine Antarctica, Argentina,
Antártica Chilena Province of Chile, and
British Antarctic Territory of the United Kingdom |
| Lower Grey Cloud | Minnesota | United States |
| Loyalty | a dependency of the French territory of New Caledonia | France |
| Lucas | Lake Huron, Ontario | Canada |
| Lucas | Western Australia | Australia |
| Luing | Inner Hebrides | Scotland |
| Lummi Island | San Juan Islands, Washington | United States |
| Lunga | Inner Hebrides | Scotland |
| Lunna Holm | Shetland Islands | Scotland |
| Lupa-sziget | | Hungary |
| Lusty Beg | Lower Lough Erne | Ireland |
| Lusty more | Lower Lough Erne | Ireland |
| Lütjehörn | East Frisian Islands | Germany |
| Luzon | Luzon | Philippines |
| Lyal | Lake Huron, Ontario | Canada |
| Lyø | | Denmark |
| Ly Son | | Vietnam |