| Lagunienu | |
| Pushpin Map: | Corsica#France |
| Subdivision Type1: | Country |
| Subdivision Name1: | France |
| Subdivision Type2: | Region |
| Subdivision Name2: | Corsica |
| Subdivision Type3: | Department |
| Subdivision Name3: | Corse-du-Sud |
| Mouth: | Tyrrhenian Sea |
The Lagunienu is a small coastal stream in the southeast of the department of Corse-du-Sud, Corsica, France.
The Lagunienu is long.It flows through the commune of Porto-Vecchio.There are no named tributaries.The stream rises to the northwest of the hamlet of Renajolo and flows in a generally southeast direction past the village of Palavesa to enter the Golfe de Porto-Vecchio between Poretta and Marina di Fiori.There are east-facing beaches on either side of the mouth of the Lagunienu.