Satyrium spini, the blue spot hairstreak, is a butterfly in the family Lycaenidae.

[1] Subspecies include:[1] The blue spot hairstreak lives in southern and middle Europe (Portugal, Spain, France, Italy, Switzerland, Austria, Germany, Poland, Hungary, Croatia, Greece, Turkey) up to approximately 54° N. It is also found in Asia Minor, Lebanon, Iraq, Iran, South Urals.

It is not found in the northwest of France, the Netherlands, Scandinavia, Estonia or Latvia.

[1][2] It inhabits open shrubby places, grassy areas, mountain meadows and woodland clearings, from low levels to about 2000 m.[3] Satyrium spini has frontwings reaching 14–16 millimetres (0.55–0.63 in) in males, 15–17 millimetres (0.59–0.67 in) in females.

The underside of forewings and hindwinhs is crossed by a bright white transverse line.