| Geru | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Galați County |
| Length: | 62km (39miles) |
| Source1: | Brătulești Hill |
| Source1 Coordinates: | 45.9344°N 27.7614°W |
| Source1 Elevation: | 227m (745feet) |
| Mouth: | Siret |
| Mouth Location: | Independența |
| Mouth Coordinates: | 45.4484°N 27.7514°W |
| Mouth Elevation: | 6m (20feet) |
| Basin Size: | 755km2 |
| Tributaries Left: | Gerusița, Gologan, Vameș, Suhu |
The Geru (in Romanian; Moldavian; Moldovan pronounced as /ˈd͡ʒeru/) is a left tributary of the river Siret in Romania. It discharges into the Siret near Independența. Its length is 62km (39miles) and its basin size is 755km2. Before the regularization of the lower course of the Siret, it was a tributary of the Bârlădel, a secondary branch of the Siret.[1] Since the regularization works, the Geru discharges directly into the Siret, and the remaining course of the Bârladel collects the left Siret tributaries to the east of the Geru and the Suhu. The Geru flows through the villages Mândrești, Valea Mărului, Cudalbi, Costache Negri, Tudor Vladimirescu, Vameș, Piscu and Independența.