Oamaru (Listeni/ɒməˈruː/; (Māori: Te Oha-a-Maru), the largest town in North Otago, in the South Island of New Zealand, is the main town in the Waitaki District. It is 80 kilometres south of Timaru and 120 kilometres north of Dunedin, on the Pacific coast, and State Highway 1 and the railway Main South Line connect it to both. With a population of 13,850, Oamaru is the 28th largest urban area in New Zealand, and the third largest in Otago behind Dunedin and Queenstown.
The name Oamaru derives from Māori words meaning the place of Maru (compare with Timaru). The identity of Maru remains open to conjecture.