The Largest Islands in the United States

From the Big Island of Hawaiʻi to Kodiak, ranked by area.

The largest islands in the United States are a mix of volcanic giants in Hawaiʻi, rugged Alaskan islands and long Atlantic barrier and glacial islands. Ranked here by land area.

#	Place	Area (sq mi)
1	The Aleutian Islands A volcanic arc reaching from Alaska toward Asia	6,821 sq mi 17,666 km²
2	Island of Hawaiʻi The Big Island, youngest and largest in the Hawaiian chain	4,027 sq mi 10,430 km²
3	Kodiak Island Alaska’s Emerald Isle and home of the Kodiak brown bear	3,595 sq mi 9,311 km²
4	Long Island The most populous island in the United States	1,377 sq mi 3,567 km²
5	Maui The Valley Isle, rebuilding after the 2023 Lahaina fire	727 sq mi 1,883 km²
6	Oʻahu The Gathering Place, home to Honolulu and two-thirds of Hawaii’s people	597 sq mi 1,545 km²
7	The Channel Islands California's "Galapagos" off the Southern coast	347 sq mi 900 km²
8	San Juan Islands Washington’s rain-shadowed archipelago between Puget Sound and Vancouver Island	174 sq mi 450 km²
9	The Florida Keys A coral archipelago curving off the tip of Florida	137 sq mi 356 km²
10	Martha's Vineyard Massachusetts island of six towns and the Wampanoag homeland of Aquinnah	97 sq mi 250 km²
11	Nantucket The former whaling capital 30 miles off Cape Cod	48 sq mi 124 km²
12	Mackinac Island The car-free island at the meeting of Lakes Huron and Michigan	4 sq mi 10 km²

Place

Area (sq mi)

The Aleutian Islands
A volcanic arc reaching from Alaska toward Asia

6,821 sq mi
17,666 km²

Island of Hawaiʻi
The Big Island, youngest and largest in the Hawaiian chain

4,027 sq mi
10,430 km²

Kodiak Island
Alaska’s Emerald Isle and home of the Kodiak brown bear

3,595 sq mi
9,311 km²

Long Island
The most populous island in the United States

1,377 sq mi
3,567 km²

Maui
The Valley Isle, rebuilding after the 2023 Lahaina fire

727 sq mi
1,883 km²

Oʻahu
The Gathering Place, home to Honolulu and two-thirds of Hawaii’s people

597 sq mi
1,545 km²

The Channel Islands
California's "Galapagos" off the Southern coast

347 sq mi
900 km²

San Juan Islands
Washington’s rain-shadowed archipelago between Puget Sound and Vancouver Island

174 sq mi
450 km²

The Florida Keys
A coral archipelago curving off the tip of Florida

137 sq mi
356 km²

Martha's Vineyard
Massachusetts island of six towns and the Wampanoag homeland of Aquinnah

97 sq mi
250 km²

Nantucket
The former whaling capital 30 miles off Cape Cod

48 sq mi
124 km²

Mackinac Island
The car-free island at the meeting of Lakes Huron and Michigan

4 sq mi
10 km²

Figures are drawn from standard government and reference sources and shown in both imperial and metric units. See each entry for full details and citations. Browse all guides or open the explore map.