The Izvorska reka (Bulgarian: Изворска река) is a 35 km long river in eastern Bulgaria that flows into Lake Burgas, which drains into the Black Sea.

[1] The river takes its source under the name Selska reka at an altitude of 386 m in the Bosna Ridge in the northern part of the Strandzha mountain range, some 3.5 km southwest of the village of Indzhe Voivoda.

It flows in direction north-northeast in a deep valley, which unlike most others in Strantdzha is not densely forested.

The Izvorska reka flows into Lake Mandrensko some 1.8 km southwest of the village of Tvarditsa.

There are six villages along its course, Indzhe Voivoda, Krushevets and Izvor, all of them in Sozopol Municipality.