Annette Island or Tàakw.àani (Tlingit) is an island in the Gravina Islands of the Alexander Archipelago of the Pacific Ocean on the southeastern coast of the U.S. state of Alaska. It is at 55°08′06″N 131°27′21″W / 55.13500°N 131.45583°W / 55.13500; -131.45583. It is about 18 km (11 mi) long and about 18 km (11 mi) wide. The land area is 332.573 km² (128.407 sq mi). Annette Island is located west across the Revillagigedo Channel from the Alaska mainland and south of Revillagigedo Island. The Island was named in 1879 by William Healey Dall, an American naturalist and explorer in Alaska, in honor of his wife Annette Whitney Dall.

The meaning of the Tlingit name for the island is Winter Town. Since the late 19th century, it has been the base of the Annette Island Reserve of the Metlakatla Alaska Native Community, composed mostly of Tsimshian people. This is the only Indian reservation in Alaska as Metlakatla voted to opt out of giving up their lands under the Alaska Native Claims Settlement Act of the 1970s. In 2016 they elected Audrey Hudson as their first Tribal Chairwoman.

The largest settlement on the island is Metlakatla. The federally recognized Metlakatla Indian Community was founded by an unordained Anglican missionary William Duncan and Tsimshian followers who moved with him from their community of Metlakatla in British Columbia after he developed new doctrine and schismatized from his church.

Since the late 19th century, the entire island has been an Indian reserve, a status enacted by Congress when the Tlingit agreed to let the Tsimshian use this territory.

The Tsimshian set up their government under the Indian Reorganization Act (1934), writing a constitution for electoral government. They have a twelve-person Council. "The mayor, secretary, and treasurer are elected by the general voting membership of the community. Each of these is elected for a two-year term. Council seats are staggered, resulting in the election of six Council seats each year and three executives every second year."

Since the late 1970s, this has been the only remaining reservation in Alaska, as the Metlakatla opted out of giving up their lands for payment under the Alaska Native Claims Settlement Act.

In 2016 its Tribal Chairwoman is Audrey Hudson, the first woman to be elected to this role. She also serves as mayor, city manager, and police commissioner of the Metlakatla Indian Community.

The island's population was 1,447 at the 2000 census. The island population is composed mainly of Tsimshian people. It is a cultural crossroads for Tlingit and Haida Natives as well.