Mount Baker, also known as Koma Kulshan or simply Kulshan, is a 10,781 ft (3,286 m) active glacier-covered andesitic stratovolcano in the Cascade Volcanic Arc and the North Cascades of Washington in the United States. Mount Baker has the second-most thermally active crater in the Cascade Range after Mount St. Helens. About 30 miles (48 km) due east of the city of Bellingham, Whatcom County, Mount Baker is the youngest volcano in the Mount Baker volcanic field. While volcanism has persisted here for some 1.5 million years, the current volcanic cone is likely no more than 140,000 years old, and possibly no older than 80–90,000 years. Older volcanic edifices have mostly eroded away due to glaciation.

An active volcano is a volcano that has erupted during the Holocene, is currently erupting, or has the potential to erupt in the future. A volcano that is not currently erupting but could erupt in the future is known as a dormant volcano. Volcanoes that will not erupt again are known as extinct volcanoes.