The Semidi Islands are a group of islands of the state of Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

, USA, lying offshore in the Gulf of Alaska

Gulf of Alaska

The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...

. The islands are part of Kodiak Island Borough

Kodiak Island Borough, Alaska

-National protected areas:* Alaska Maritime National Wildlife Refuge ** Barren Islands** Semidi Wilderness*** Semidi Islands** Trinity Islands*** Sitkinak Island*** Tugidak Island...

 and are located southwest of Kodiak Island

Kodiak Island

Kodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...

, about half way between the Alaska Peninsula

Alaska Peninsula

The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....

 mainland and Chirikof Island

Chirikof Island

Chirikof Island is located in the Gulf of Alaska approximately southwest of Kodiak Island.-Terrain:Chirikof Island consists of of grasses and sedges. Treeless, it lies west of the western tree line in Alaska. The island is shaped like a swim fin with the heel to the north and the webbing to the...

. The largest islands of the group are Aghiyuk Island and Chowiet Island. The island group has a total land area of 30.178 km² (11.652 sq mi) and are uninhabited. They are part of the Alaska Peninsula unit of the Alaska Maritime National Wildlife Refuge

Alaska Maritime National Wildlife Refuge

The Alaska Maritime National Wildlife Refuge is a United States National Wildlife Refuge comprising 2,400 islands, headlands, rocks, islets, spires and reefs in Alaska, with a total area of , of which is wilderness)...

.