The Tya is a river located in the municipality of Tydal in Trøndelag county, Norway. The 16.3-kilometre (10.1 mi) long river flows from the lake Stuggusjøen near the village of Stugudalen and flows north to the village of Ås where it joins the Nea River. It is part of the Nea-Nidelvvassdraget river system. The river has a watershed of about 287 square kilometres (111 sq mi). The river flows at an average rate of 8.64 cubic metres per second (305 cu ft/s).