Alagogshak is a stratovolcano, located on the Alaska Peninsula, United States, in Katmai National Park and Preserve.

It is the oldest of the volcanoes in the vicinity of the Valley of Ten Thousand Smokes.

The volcano was recognized as a separate feature from Mount Martin in 1997.

[1][3] The remnant summit crater consists of hydrothermally altered rock.

It is the only member of the Katmai volcanic group that is no longer active.