| Flumini Mannu | |
| Mouth: | Stagno di Cagliari |
| Mouth Coordinates: | 39.2633°N 9.0105°W |
| Progression: | Stagno di Cagliari→ Tyrrhenian Sea |
| Subdivision Type1: | Country |
| Subdivision Name1: | Italy |
| Length: | 42km (26miles) |
The Flumini Mannu is a river in southern Sardinia, Italy.
Its springs are located in the hills east of Sardara. It flows into the Stagno di Cagliari after a course of 42.14km (26.18miles). The river's main tributaries are the Riu Bellu and the Rio Sitzerri, which for most of the basin of Monte Linas massif's waters.