The Flumendosa is a river of southern Sardinia, Italy. With a length of 127 kilometres, it is the second longest river of the island behind the Tirso.
The Flumendosas springs are located in the Gennargentu massif, at the foot of the Monte Armidda; it flows into the Tyrrhenian Sea near the towns of Muravera and Villaputzu. It drains a basin of about 1,775 square kilometres. Before the construction of two large dams, it had a discharge of 22 cubic metres per second.
