Silda (Northern Sami: Sildi) is an uninhabited island in Loppa Municipality in Troms og Finnmark county, Norway. The 48-square-kilometre (19 sq mi) island lies in the Lopphavet Sea, north of the villages of Bergsfjord and Sør-Tverrfjord on the mainland. The island is very mountainous, the tallest being the 628-metre (2,060 ft) tall mountain Sunnáčohkka. The name of the island may be derived from the Norwegian words for "seal" or "herring". Archaeological findings on the islands include farm mounds, traces of houses, burial cairns from the Iron Age and Middle Ages.