Sathyamangalam Wildlife Sanctuary and Tiger Reserve is a protected area and Tiger Reserve along the Western Ghats in the Indian state of Tamil Nadu.

Largest among the four tiger reserves (Kalakad-Mundanthurai, Annamalai, Mudumalai and Sathyamangalam) in Tamil Nadu, STR is a significant wildlife corridor in the Nilgiri Biosphere Reserve between the Western Ghats and the rest of the Eastern Ghats, serving as a genetic link to contiguous protected areas including the Biligiriranga Swamy Temple Wildlife Sanctuary, Sigur Plateau, Mudumalai National Park and Bandipur National Park.