Carmen de Patagones is a city in the province of Buenos Aires, Argentina. It is the southernmost city in the province, located in the far south of Buenos Aires territory near the boundary with Río Negro Province.
The city sits on the northern bank of the Río Negro, across from the city of Viedma, the capital of Río Negro Province. The two cities face each other across the river and together form a single urban area, though they belong to different provinces.
Carmen de Patagones is one of the oldest settlements in the region, founded during the colonial period as a fort and settlement on the edge of Patagonia. Its historic centre preserves buildings from the eighteenth and nineteenth centuries, and it is known for its connection to the early Argentine presence in Patagonia.