The Flumendosa is a river of southern Sardinia, Italy. With a length of 127 kilometres (79 mi), it is the second longest river of the island behind the Tirso.

Flumendosa
Lake of Basso Flumendosa
Location
Country	Italy
Physical characteristics
Source
• location	Monte Armidda (Gennargentu massif)
• elevation	1,270 m (4,170 ft)
Mouth	Tyrrhenian Sea
• location	near Muravera and Villaputzu
• coordinates	39°25′47″N 9°37′45″E / 39.4298°N 9.6291°E / 39.4298; 9.6291
• elevation	0 m (0 ft)
Length	127 km (79 mi)
Basin size	1,775 km2 (685 sq mi)

The Flumendosa's 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 (685 sq mi). Before the construction of two large dams, it had a discharge of 22 cubic metres per second (780 cu ft/s).