| Type: | commune |
| County: | Bacău |
| Population Total: | auto |
| Oituz | |
| Leader Name: | Claudiu Petrișor[1] |
| Leader Party: | PNL |
| Term: | 2020 - 2024 |
| Coordinates: | 46.2°N 63°W |
| Elevation: | 279 |
| Area Total: | 202.23 |
Oituz (formerly Grozești; Hungarian: Gorzafalva) is a commune in Bacău County, Western Moldavia, Romania. It is composed of six villages: Călcâi (Zöldlonka), Ferestrău-Oituz (Fűrészfalva), Hârja (Herzsa), Marginea, Oituz and Poiana Sărată (Sósmező).
Oituz was the site of three battles during the First World War: the First, Second, and the Third Battle of Oituz.
According to Iorgu Iordan, the commune's name is of Turkic origin; otuz or oltuz means "thirty" in some Turkic languages.[2] [3] [4]
Poiana Sărată village is part of Transylvania;[5] in Austria-Hungary, it belonged to Háromszék County, and after a reorganization to Trei Scaune County in Romania until 1950.
At the 2002 census, 99.8% of inhabitants were ethnic Romanians and 0.2% Hungarians. 49.2% were Romanian Orthodox, 48.9% Roman Catholic and 1.8% Seventh-day Adventist.