The Engadine Line is an over 50-kilometre (30 mi) long strike-slip fault in the Swiss canton of Graubünden, which extends into Italy and Austria. It runs along the Engadine Valley (which formed on the fault) and the Bregaglia Valley and offsets Austroalpine and Penninic units in a sinistral direction. The western end of the fault appears to peter out into ductile deformation in the Bregaglia Valley or continues as the Gruf Line to the southwest; the eastern end is buried by the Ötztal tectonic block and may continue as the "Inntal fault", "Isar fault" or "Loisach fault".
Total offset along the Engadine Line is about 4–20 kilometres (2–12 mi), decreasing southwest. It began in the Oligocene, but there is evidence of recent neotectonic activity, which resulted in the collapse of the Maloja Pass area at the beginning of the Holocene. Seismic activity occurs along the Engadine Line, and springs and carbon dioxide exhalations in the Engadine are linked to the fault.