Polyommatus golgus, the Sierra Nevada blue, is a species of butterfly in the family Lycaenidae.

It is endemic to Spain with habitat in the Sierra Nevada in Andalusia (Granada and Almería provinces), and is an endangered species.

It is a small butterfly (forewing length is 11 to 16 mm) that has a sexual dimorphism, the upperside of the male is bright blue to light sky blue , that of the female is brown, decorated with a submarginal line of large orange macules.

The underside is light ochre to brownish-grey adorned with a submarginal line of white lunula centred by a more or less marked black point and discreetly surrounded by orange.

Submarginal lunules are of pale orange colour, they are variable in number and size and close to them are noticeable black marginal spots.