The Untersberg is a mountain massif of the Berchtesgaden Alps that straddles the border between Berchtesgaden, Germany and Salzburg, Austria.
The mountain is popular with tourists due to its proximity to the city of Salzburg: less than 16 km (10 mi) to the north and within easy reach by bus. Trails lead to the top, but most people use the cable car that lifts passengers over 1300m to the Geiereck peak.
The first recorded ascent was in the first half of the 12th century, by Eberwein, a member of the Augustinian monastery at Berchtesgaden.
The mountain lends its name to an 1829 opera, Der Untersberg, by Johann Nepomuk (1783–1865), Baron of Poissl, and has inspired a series of works by German artist Stephan Hess.