The Oituz (Hungarian: Ojtoz) is a right tributary of the river Trotuș in Romania. It discharges into the Trotuș in Onești. The following towns and villages are situated along the river Oituz, from source to mouth: Oituz (CV), Poiana Sărată, Oituz (BC), Bogdănești and Onești. Its length is 62 km (39 mi) and its basin size is 337 km (130 sq mi).