The Nilgiri tahr is an ungulate that is endemic to the Nilgiri Hills and the southern portion of the Western and Eastern Ghats in the states of Tamil Nadu and Kerala in southern India. It is the only species in the genus Nilgiritragus and is closely related to the sheep of the genus Ovis.

The Nilgiri Mountains form part of the Western Ghats in northwestern Tamil Nadu, Southern Karnataka, and eastern Kerala in India. They are located at the trijunction of three states and connect the Western Ghats with the Eastern Ghats. At least 24 of the Nilgiri Mountains' peaks are above 2,000 metres (6,600 ft), the highest peak being Doddabetta, at 2,637 metres (8,652 ft).