Mont Mars (Italian: Monte Mars or Mont Mars locally; from French) at 2,600 m, is the highest peak of the Biellese Alps, north-western Italy.

It is located on the water divide between the Lys Valley (Aosta Valley) and the Elvo Valley (Province of Biella).

In the SOIUSA (International Standardized Mountain Subdivision of the Alps) it gives the name to a mountain group called "Catena Tre Vescovi - Mars".

It gives its name to a nearby nature reserve, the Mont Mars Nature Reserve (Italian: Riserva Naturale Mont Mars; French: Réserve naturelle du mont-Mars).

It can be ascended from the south, starting from the Sanctuary of Oropa or, from the North, starting from the Lys Valley. The summit provides a panorama across the plains of the Po Valley and of the Monte Rosa massif.