Austmarka is a village in Alver Municipality in Vestland county, Norway. The village is located on the southern end of the island of Radøy, about 2 kilometres (1.2 mi) east of the village of Sæbø and about 5 kilometres (3.1 mi) north of the village of Alverstraumen.

Prior to 2020, the village was part of Radøy Municipality.

The 0.25-square-kilometre (62-acre) village has a population (2025) of 464 and a population density of 1,856 inhabitants per square kilometre (4,810/sq mi).