Kanakas were workers (a mix of voluntary and involuntary) from various Pacific Islands employed in British colonies, such as British Columbia (Canada), Fiji, Solomon Islands, Vanuatu, Papua New Guinea, and Queensland (Australia) in the 19th and early 20th centuries. They also worked in California (United States) and Chile (see also Easter Island and the Rapa Nui).

"Kanaka" originally referred only to Native Hawaiians, from their own name for themselves, kānaka ʻōiwi or kānaka maoli, kānaka meaning "man" in the Hawaiian language. In the Americas in particular, native Hawaiians were the majority; but Kanakas in Australia were almost entirely Melanesian. In Australian English "kanaka" is now avoided outside of its historical context, as it has been used as an offensive term.

According to the Macquarie Dictionary, the word "kanaka", which was once widely used in Australia, is now regarded in Australian English as an offensive term for a Pacific Islander. Most "Kanakas" in Australia were people from Melanesia, rather than Polynesia. The descendants of 19th century immigrants to Australia from the Pacific Islands now generally refer to themselves as "South Sea Islanders", and this is also the term used in formal and official situations.

Most of the original labourers were recruited or blackbirded (kidnapped or deceived) from the Solomon Islands, New Hebrides (Vanuatu) and New Caledonia, with others from the Loyalty Islands.

The first shipload of 65 Melanesian labourers arrived in Boyd Town on 16 April 1847 on board the Velocity, a vessel under the command of Captain Kirsopp and chartered by Benjamin Boyd. Boyd was a Scottish colonist who wanted cheap labourers to work at his expansive pastoral leaseholds in the colony of New South Wales. He financed two more procurements of South Sea Islanders, 70 of which arrived in Sydney in September 1847, and another 57 in October of that same year. Many of these Islanders soon absconded from their workplaces and were observed starving and destitute on the streets of Sydney. After the report of the alleged murder of the Native Chief of the Island of Rotumah in 1848, a closed-door enquiry was held, choosing not to take any action against Boyd or Kirsopp. The experiment of utilising Melanesian labour was discontinued in Australia until Robert Towns recommenced the practice in the early 1860s.

After 1863, more than 62,000 Islanders were brought to Australia; in 1901, about 10,000 were living in Queensland and northern New South Wales. The Pacific Island Labourers Act 1901, legislation complementing the White Australia policy, ordained the deportation of all post-1879 arrivals to the Solomon Islands or the New Hebrides, where "neither property, nor rights, nor welcome awaited them". Antonius Tua Tonga, a Kanaka who had lived in Queensland since the age of four, petitioned the King of England for a mitigation of the legislation, but the Australian prime minister, Alfred Deakin, advised the British government the petition was a front for planters, and the deportations took place largely as intended. A legislative amendment in 1905 exempted those of "extreme age", those married to whites, and freeholders. The prime minister, Alfred Deakin, declined to exempt those schooled in Australia.

The descendants of those who avoided deportation today form Australia's largest Melano-Polynesian ethnic group. Many Australian South Sea Islanders are also of mixed ancestry, including Aboriginal and Torres Strait Islanders, for whom they are often mistaken. As a consequence, Australian South Sea Islanders have faced forms of discrimination similar to Aboriginals and Torres Strait Islanders.

After 1994, the Australian South Sea Islander community was recognised as a unique minority group, following a report by the Australian Human Rights and Equal Opportunity Commission, which found they had become more disadvantaged than indigenous Australians.