Sømna Church is a log church with predominantly tall rectangular crossmullioned windows with arched glazing bars in the two upper casements. The latter as well as other decorative details indicates links to the ideals of gothic revival. The church tower is square with an octagonal spire to the west. The chancel and the sacristy are to the east. The church rests on low rendered stone foundations. The walls are square sawn and planed logs with vertical external cladding. The exterior is white with ochre details.