| Flumendosa | |
| Source1 Location: | Monte Armidda (Gennargentu massif) |
| Mouth: | Tyrrhenian Sea |
| Mouth Location: | near Muravera and Villaputzu |
| Mouth Coordinates: | 39.4298°N 9.6291°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Italy |
| Length Km: | 127 |
| Source1 Elevation: | 1270m (4,170feet) |
| Mouth Elevation: | 0m (00feet) |
| Basin Size Km2: | 1775 |
The Flumendosa is a river of southern Sardinia, Italy. With a length of 127km (79miles), it is the second longest river of the island behind the Tirso.
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 1775km2. Before the construction of two large dams, it had a discharge of 22m3/s.