Mahasu Devta Temple (Mahasui: 𑚢𑚩𑚭𑚨𑚱 𑚛𑚲𑚦𑚙𑚭 𑚢𑚫𑚛𑚮𑚤, Hindi: महासू देवता मंदिर), is located on the Tyuni-Mori road at Hanol, Dehradun district, Uttarakhand, India and was built in the 9th century. The temple is dedicated to Mahasu Devta. The temple was constructed in the Kath-Kuni or Koti-Banal style of architecture and is included in the Archaeological Survey of India's list of the ancient temple in the Dehradun circle, Uttarakhand.

Mahasu Devta Temple is on the eastern bank of Tons River (Tamas) at Hanol village, near Chakrata, about 190 km from Dehradun, 156 km from Mussoorie and about 140 km from Shimla.