Geltsdale is a hamlet and former civil parish, now in the parish of Castle Carrock, in the Cumberland district, in the ceremonial county of Cumbria, England, to the southeast of Castle Carrock village.

[2] On 1 April 2003 the parish was abolished and merged with Castle Carrock.

[3][4] The Geltsdale Reservoir railway ran in the vicinity.

Two of the protected areas cover a large area: Geltsdale & Glendue Fells Site of Special Scientific Interest has an area of 8,059 ha,[6] and is one of the SSSIs which underlie the SPA.

It mainly moorland and is managed by the Royal Society for Protection of Birds for upland birds such as black grouse and hen harrier.