Byavatnet is a lake in the municipality of Levanger in Nord-Trøndelag county, Norway. It is located about 2.5 kilometres (1.6 mi) south of the village of Ekne and about 3 kilometres (1.9 mi) west of Ronglan. The lake Hammervatnet lies about 3.5 kilometres (2.2 mi) south of Byavatnet and the lake Sønningen lies about 1.5 kilometres (0.93 mi) to the northwest. The 2.31-square-kilometre (570-acre) lake is about 5 kilometres (3.1 mi) long and about 800 metres (0.5 mi) wide.