Tya is a river located in Tydal Municipality in Trøndelag county, Norway. The long river flows from the lake Stuggusjøen near the village of Stugudalen and flows north through the Tydalen valley to the village of às where it joins the Nea River. It is part of the Nea-Nidelvvassdraget river system. The river has a watershed of about . The river flows at an average rate of .