Seltjarnarnes (Icelandic pronunciation: [ˈsɛlˌtʰja(r)tnarˌnɛːs]) is a town in the Capital Region of Iceland. Seltjarnarnes is adjacent to Reykjavik.
It took on its current political form shortly after the Second World War and was formally created as a township in 1947. It is the smallest Icelandic township by land. The municipality's small land size relative to its population makes it Iceland's most densely populated municipality.