Ytre Sandsvær is a former municipality in Buskerud county, Norway.
It was created when Sandsvær was split into Ytre and Øvre Sandsvær on 1 January 1908. At that time Ytre Sandsvær had a population of 3,245.
On 1 January 1964 the two municipalities were incorporated into Kongsberg municipality. Prior to the merger Ytre Sandsvær had a population of 3,140.