Belasitsa or Belasitza, Ottoman Turkish:[1] بلش Turkish: Beleş), Belles (Greek: Μπέλλες, Bélles) or Kerkini (Greek: Κερκίνη, Kerkíni;), is a mountain range in the region of Macedonia in Southeastern Europe, shared by northeastern Greece (about 45%), southeastern North Macedonia (35%) and southwestern Bulgaria (20%).

The highest point is Radomir (Kalabaka) at 2,031 m, with elevation otherwise ranging between 300 and 1900 m above sea level.

Two football teams are named after the mountain range, PFC Belasitsa from the nearby Bulgarian town of Petrich and FC Belasica from Strumica in North Macedonia.

[2][3] According to the ancient authors it was a mountain range in the border area between Thrace and Macedonia.

[7] The area is also particularly famous for the Battle of Kleidion of 1014, which proved crucial for the fall of the First Bulgarian Empire.