In geology, a massif is a section of the Earth's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term is also used to refer to a group of mountains formed by such a structure. The massif is a smaller structural unit of the crust than a plate.

The word is taken from French, where it is used to refer to a large mountain mass or compact group of connected mountains forming an independent portion of a range. One of the most notable European examples of a massif is the Massif Central of the Auvergne region of France.

• Armorican Massif - Brittany, France
• Annapurna Massif - Nepal
• Atlantis Massif - part of the Mid-Atlantic Ridge in the North Atlantic Ocean.
• Chartreuse Massif - France
• Kugitangtau Ridge - Turkmenistan
• Laurentian Massif - Quebec, Canada (French: Massif des Laurentides)
• Massif Central - France
• Massif Montgris - Spain
• Vinson Massif - Antarctica

In mountaineering and climbing literature, a massif is frequently used to denote the main mass of an individual mountain.