Rio Tinto Group is an Anglo-Australian multinational company that is the world's second-largest metals and mining corporation (behind BHP). The company was founded in 1873 when of a group of investors purchased a mine complex on the Rio Tinto, in Huelva, Spain, from the Spanish government. It has grown through a long series of mergers and acquisitions. Although primarily focused on extraction of minerals, Rio Tinto also has significant operations in refining, particularly the refining of bauxite and iron ore. Rio Tinto has joint head offices in London (global and "plc") and Melbourne ("Limited" – Australia).

Rio Tinto is a dual-listed company traded on both the London Stock Exchange, where it is a component of the FTSE 100 Index, and the Australian Securities Exchange, where it is a component of the S&P/ASX 200 index. Additionally, American depositary shares of Rio Tinto's British branch are traded on the New York Stock Exchange, giving it listings on a total of three major stock exchanges. In the 2020 Forbes Global 2000, Rio Tinto was ranked as the 114th-largest public company in the world.

In May 2020, to expand the Brockman 4 mine, Rio Tinto demolished a sacred cave in Juukan Gorge, Western Australia, which had evidence of 46,000 years of continual human occupation, and was considered the only inland site in Australia to show signs of continual human occupation through the last Ice Age. Rio Tinto later apologised for the distress caused and CEO Jean-Sébastien Jacques subsequently stepped down.

Rio Tinto has been widely criticised by environmental groups as well as the government of Norway for the environmental impacts of its mining activities: claims of severe environmental damages related to Rio Tinto's engagement in the Grasberg mine in Indonesia led the Government Pension Fund of Norway to exclude Rio Tinto from its investment portfolio.

Academic observers have also expressed concern regarding Rio Tinto's operations in Papua New Guinea, which they allege were one catalyst of the Bougainville separatist crisis. There have also been concerns over corruption: in July 2017 the UK's Serious Fraud Office (SFO) announced the launch of a fraud and corruption investigation into the company's business practices in Guinea.