Oamaru is the largest town in North Otago, in the South Island of New Zealand, it is the main town in the Waitaki District. It is 80 kilometres (50 mi) south of Timaru and 120 kilometres (75 mi) north of Dunedin on the Pacific coast; State Highway 1 and the railway Main South Line connect it to both cities. With a population of 14,000, Oamaru is the 28th largest urban area in New Zealand, and the third largest in Otago behind Dunedin and Queenstown. The town is the seat of Waitaki District, which includes the surrounding towns of Kurow, Weston, Palmerston, and Hampden, which combined have a total population of 23,200.

Waitaki District is a territorial authority district that is located in the Canterbury and Otago regions of the South Island of New Zealand. It straddles the traditional border between the two regions, the Waitaki River, and its seat is Oamaru.