Borgarknappur, Mountain summit in Suðuroy, Faroe Islands.

Borgarknappur is a 574-metre mountain in the centre of Suðuroy, Faroe Islands, west of Hov, south-east of Fámjin, south-west of Øravík and north of Vágur. Its neighbour Borgin (570 m) stands just to the west, and Hvannafelli (558 m) lies further south. The old village paths meet below it at Mannaskarð, near Laðanfelli (487 m).

Ancient paths crossing the mountain at Mannaskarð pass served as vital communication routes between five different villages before modern roads were built. These historical routes show how important the mountain was as a central hub for human movement in the region.

The name combines Faroese borg, a fortification or castle-like rock, with knappur, a knoll or peak, matching the neighbouring summit Borgin (570 m). The old cairns along the paths are now used mainly by hikers and tourists walking between the villages.

Hiking trails to the summit begin from several villages including Øravík, Fámjin, Porkeri, Hov, and Vágur and are marked by stone cairns. The paths are reasonably clear, but weather in this region changes quickly, so hikers should prepare for variable and sometimes harsh conditions.

Borgin, a 570-metre peak, stands immediately west of Borgarknappur, and Hvannafelli (558 m) lies further south. The name Borgarknappur relates to borg, the Faroese word for a fortification or castle-like rock, a common element in Faroese mountain names.