Maraetai Rd, Tokoroa was closed last night while emergency services responded to a crash involving a single vehicle, reported around 9pm.
Police confirmed that one person died in transit to hospital after they were helicoptered from the scene in a critical condition.
The Serious Crash Unit has completed its scene examination, and enquiries into the circumstances of the crash are ongoing.
Earlier yesterday a person received critical injuries in another serious crash in South Waikato.
Police said in a statement they were called to a two-vehicle crash in Arapuni at 1.50pm.