Arapuni is a rural town centre on the Waikato river in the South Waikato District of New Zealand. The town sits next to the Arapuni Dam, a hydroelectric dam at Lake Arapuni commissioned in 1929. The Arapuni Power Station consists of eight turbines which give a total output of 196 MW, the largest of the power stations on the Waikato river. The Arapuni hydro station is owned and operated by Mercury Energy.