Rivers of Turkey can be divided into several groups depending on where they flow.
Flow into the Black Sea
- Mutludere (also known as Rezovo) flows from Turkey into Bulgaria. 112 km.
- Veleka flows into Bulgaria and then into the Black Sea. 147 km (25 km in Turkey)
- Kızılırmak 'Red River' is the longest river in Turkey, also known as the Halys River. 1,350 km
- Delice River - tributary
- Devrez River - tributary
- Gök River - tributary (also known as Gökırmak and in Classical times, Amnias)
- Sakarya River is the third longest river in Turkey, also known as Sangarius. 824 km
- Meriç (Maritsa or Evros) is in the European section of Turkey and has its source in Bulgaria. It is 480 km long.
- Tunca is a 350 km tributary in Bulgaria
- Ergene is a tributary inside of Turkey.