Tseax Cone (also called Tseax River Cone or the Aiyansh volcano) is a young cinder cone in the Northern Cordilleran Volcanic Province in British Columbia, Canada. It is the site of one of Canda's most recent eruptions, which was a major lava flow around the years 1750 or 1775. Tseax Cone's activity is present in legends and stories of the Nisga'a People.
Gas emissions from the volcano and major lava flows are the most significant hazards from Tseax Cone.