The Adirondack Mountains, known as the Adirondacks in northeastern New York, United States are a separate geological area demarcated by faults. The current relief owes much to glaciation.

The Adirondack Mountain boundaries correspond to the boundaries of Adirondack Park. The mountains form a roughly circular dome, about 160 miles (260 km) in diameter and about 1 mile (1,600 m) high.

The highest peaks in the Adirondacks include Mount Marcy (5344 feet), Algonquin Peak (5114 feet), Mount Haystack (4960 feet), Mount Skylight (4920 feet), and Whiteface Mountain (4867 feet). The list of tall mountains include forty-two mountains over 4000 feet, two of which are over 5000 feet.