Karioi or Mount Karioi is a 2.4 million year old extinct stratovolcano 8 km SW of Raglan in the Waikato region of New Zealand's North Island. It was the earliest of the line of 6 calcalkalic volcanoes, the largest of which is Mount Pirongia (the others are at Kakepuku, Te Kawa, Tokanui, Waikeria and probably Puketotara). Karioi forms a background to many parts of Raglan. Karioi is also a location on the Central Plateau (see article on Karioi railway station).