Stamsø or Stamsøy is a village in Risør municipality in Agder county, Norway. The village is located along the north shore of the Søndeledfjordne, about 4 kilometres (2.5 mi) east of the village of Søndeled and about 3 kilometres (1.9 mi) west of the village of Sivik.

Stamsø is also a family name for a number of people in the region. The Stamsø family name has roots that can be traced several centuries back in time. There was once a school at Stamsø, but it is no longer in use.