Lochnagar or Beinn Chìochan is a mountain in the Mounth, in the Grampians of Scotland. It is about five miles south of the River Dee near Balmoral. It is a popular hill with hillwalkers, and is a noted venue for summer and winter climbing.

The Mounth is the broad upland in northeast Scotland between the Highland Boundary and the River Dee, at the eastern end of the Grampians.