The City and Borough of Sitka is a unified city-borough located on the west side of Baranof Island in the Alexander Archipelago of the Pacific Ocean (part of the Alaska Panhandle), in the U.S. state of Alaska. Sitka is the state's fourth-largest city by population and the largest city in the United States by area.

The name Sitka (derived from Sheet’ká, a contraction of the Tlingit name Shee At'iká) means "People on the Outside of Shee," Sheet’-ká X'áat'l (often expressed simply as Shee) being the Tlingit name for Baranof Island. The town is sometimes referred to as "Sitka-by-the-Sea."