The longest river that Bulgaria has a bank on is the Danube (2,888 km), which spans most of the country's northern border. The longest one to run through the country (and also the deepest) is the Maritsa (480 km), while the longest river that runs solely in Bulgaria is the Iskar (368 km).
A country rich in water resources, Bulgaria has a large number of rivers that are divided into several regions based on their mouth's location.
The rivers in the eastern part of the country are typically short (except for Kamchiya) and flow into the Black Sea. Notable rivers in the region include the Kamchiya, Batova, Provadiyska, Devnenska, Ropotamo, Veleka and Rezovska.
Most of the rivers that rise in southern Bulgaria have their mouths in the Aegean Sea outside Bulgarian territory. A notable exception is the Iskar that takes its source from Rila and runs through Stara Planina forming a gorge to reach the Danube. Depending on their location, they are divided into two regions, a Western Aegean and Eastern Aegean one. The former embraces the Struma and Mesta, while rivers in the latter include the Arda, Maritsa and Tundzha.
- Archar River
- Batova reka
- Deleynska reka
- Devil's River
- Fakiyska reka
- Kajalijka (river flowing through Iskra and Bryagovo into the Maritsa)
- Luda Reka (Bulgarian Mad River)
- Byala reka (Bulgarian: White river)
- Luda Yana (Bulgarian: Mad Yana)
- Mechka (Bulgarian: Bear)
- Provadiyska reka (Bulgarian: River of Provadia)
- Pyasachnik (Bulgarian: Sandstone)
- Rusenski Lom
- Rusokastrenska reka (Bulgarian: River of Rusokastro)
- Shirokolashka reka (Bulgarian: River of Shiroka Laka)
- Stara reka (Bulgarian: Old river)
- Suha reka (Bulgarian: Dry river)
- Topolnitsa (in Bulgarian, Topola means poplar)
- Voynishka reka (Bulgarian: Soldier's river)
- Zlatna Panega (Bulgarian: Golden Panega)
Note: in Bulgarian, reka means river.