Rjecina (Italian: Fiumara) is a river in Croatia which flows in the Adriatic sea in the city of Rijeka (Fiume). Rijeka means river in Croatian.

It is cca 19 km long, with average width of 9 - 16 m. It springs from the cave on the height of 325m above sea level, under high cliff of Kicej hill (606 m above sea level). Until 1870. the river's spring was under the next by hill called Podjavorje, but it collapsed in earthquake near village Klana. In 1968., a dam was built for the needs of hydroelectric power plant, and lake Valici came to existence, but the same name village seized to exsist. Rjecina flows through the canyon almost half of her lengh. In Rijeka, the river branches in two parts: Mrtvi kanal (the old basin) and the new canal which was made in 19th century when Mrtvi kanal was used as a harbour. Of sights, the most famous is Gaspar's watermill (Gasparov mlin) which was renewed in 90s. Of fauna the most noticeable are trouts and river crabs.

Until WW II the river was many times imposed as a border between Croatia (Yugoslavia) and part of Croatia taken by Italy.

This gallery shows walking path from Rijeka center to the river itself.