Orelyak () is a nature reserve in the central section of the Pirin mountain range in south-western Bulgaria. It is situated in Gotse Delchev Municipality, Blagoevgrad Province. It was declared on 22 February 1985 to protect old growth beech forests it the vicinities of Mount Orelyak (2,099 m), the highest summit in Central Pirin. It spans a territory of 757 ha or 7.57 km2.