Rarotonga is the most populous island of the Cook Islands, with a population of 10,572 (census 2011), out of the country's total resident population of 14,974. Captain John Dibbs, master of the colonial brig Endeavour, is credited as the European discoverer on 25 August 1823, while transporting the missionary Rev. John Williams. The Cook Islands' Parliament buildings and international airport are on Rarotonga. Because it is the most populous island, Cook Islanders may often be referred to as Rarotongan, but they may come from one of the other 14 islands in the group, such as Aitutaki or Mangaia. Rarotonga is a very popular tourist destination with many resorts, hotels and motels. The chief town, Avarua, on the north coast, is the capital of the Cook Islands.

Rarotonga / Mount Smart (also known as Te Ipu kura a Maki) is one of the volcanoes in the Auckland Volcanic Field. Quarrying removed almost all the scoria cone, which was 87 m high (around 57 m higher than the surrounding land). Prior to the arrival of Pakeha, it was extensively terraced and used as a defensive pa. The former quarry is now the site of Mount Smart Stadium.