The Ropotamo (Bulgarian: Ропотамо, from the Ancient Greek word meaning "border river") is a relatively short river in southeastern Bulgaria. It takes its source from the Strandzha Mountains, running for 48.5 kilometres (30.1 mi) to empty into the Black Sea between Dyuni and Primorsko.
The river is most often noted for its 30 m-wide mouth that is home to an abundance of flora species, over 100 of which endangered in the country. The lower section of the Ropotamo is a nature reserve since 1940 and a protected area. The lower Ropotamo is a popular tourist attraction because of the water lilies and the rock formations above the river, on some of which white-tailed eagles nest.
Ropotamo Glacier on Livingston Island in the South Shetland Islands, Antarctica is named after Ropotamo River.