Donald Allan Dunstan AC QC (21 September 1926 – 6 February 1999) was an Australian politician who served as the 35th premier of South Australia from 1967 to 1968, and again from 1970 to 1979. He was a member of the House of Assembly (MHA) for the division of Norwood from 1953 to 1979, and leader of the South Australian Branch of the Australian Labor Party from 1967 to 1979. Before becoming premier, Dunstan served as the 38th attorney-general of South Australia and the treasurer of South Australia. He is the fourth longest serving premier in South Australian history.

In the late 1950s, Dunstan became well known for his campaign against the death penalty being imposed on Max Stuart, who was convicted of rape and murder of a small girl, opposing then-Premier Thomas Playford over the matter. During Labor's time in opposition, Dunstan was prominent in securing some reforms in Aboriginal rights and in Labor abandoning the White Australia policy. Dunstan became Attorney-General after the 1965 election, and replaced the older Frank Walsh as premier in 1967. Despite maintaining a much larger vote over the Liberal and Country League (LCL), Labor lost two seats at the 1968 election, with the LCL forming government with support of an independent. Dunstan responded by increasing his attacks on the Playmander, convincing the LCL into watering down the malapportionment. With little change in Labor's vote but with the Playmander removed, Labor won 27 of 47 seats at the 1970 election, and again in 1973, 1975, and 1977.

Dunstan's socially progressive administration saw Aboriginal land rights recognised, homosexuality decriminalised, the first female judge (Dame Roma Mitchell) appointed, the first non-British governor, Sir Mark Oliphant, and later the first Indigenous governor, Sir Douglas Nicholls. He enacted consumer protection laws, reformed and expanded the public education and health systems, abolished the death penalty, relaxed censorship and drinking laws, created a ministry for the environment, enacted anti-discrimination law, and implemented electoral reforms such as the overhaul of the Legislative Council, the upper house of Parliament, lowered the voting age to 18, enacted universal suffrage, and completely abolished malapportionment. He also established Rundle Mall, enacted measures to protect buildings of historical heritage, and encouraged arts, with support for the Adelaide Festival Centre, the State Theatre Company, and the establishment of the South Australian Film Corporation.

At the same time, there were also problems; the economy began to stagnate, and the large increases to burgeoning public service generated claims of waste. One of Dunstan's pet projects, a plan to build a new city at Monarto to alleviate urban pressures in Adelaide, was abandoned when economic and population growth stalled, with much money and planning already invested. After four consecutive election wins, Dunstan's administration began to falter in 1978 following his dismissal of Police Commissioner Harold Salisbury, as controversy broke out over whether he had improperly interfered with a judicial investigation. In addition, policy problems and unemployment began to mount, as well as unsubstantiated rumours of corruption and personal impropriety. The strain on Dunstan was increased by the death of his wife. His resignation from the premiership and politics in 1979 was abrupt after collapsing due to ill health, but he lived for another 20 years, remaining a vocal and outspoken campaigner for progressive social policy.

Donald Allan Dunstan was born on 21 September 1926 in Suva, Colony of Fiji, the son of Francis Vivian Dunstan and Ida May Dunstan (née Hill), Australians of Cornish descent. His parents had moved to Fiji in 1916 after his father took up a position as manager of the Adelaide Steamship Company. He spent the first seven years of his life in Fiji, starting his schooling there. Dunstan was beset by illness, and his parents sent him to South Australia hoping the drier climate would assist his recovery. He lived in Murray Bridge for three years with his mother's parents before returning to Suva for a short period during his secondary education. During his time in Fiji, Dunstan mixed easily with the Indian settlers and indigenous people, something that was frowned upon by many of the white people on the islands.

Dunstan won a scholarship in classical studies and attended St Peter's College, a traditional private school for the sons of the Adelaide establishment. He developed public speaking and acting skills, winning the college's public speaking prize for two consecutive years. In 1943, he portrayed the title role in a production of John Drinkwater's play Abraham Lincoln, and according to the school magazine, he "was the chief contributor to the success of the occasion". His academic strengths were in classical history and languages, and he disliked mathematics. He gained a reputation as a maverick. During this time, Dunstan did not board and lived in the seaside suburb of Glenelg with relatives. Dunstan completed his secondary schooling in 1943, ranking in the top 30 overall in the statewide matriculation examinations.

In his youth, influenced by his uncle, former Liberal Lord Mayor of Adelaide Sir Jonathan Cain, Dunstan was a supporter of the conservative Liberal and Country League (LCL) and handed out how-to-vote cards for the party at state elections. Dunstan later said of his involvement with the Liberals: "I do not call it snobbery to deride the Establishment in South Australia, I admit that I was brought up into it, and I admit that it gave me a pain." When asked of his roots, he said, "I'm a refugee from it and thank God for somewhere honest to flee to!"

His political awakening happened during his university years. Studying law and arts at the University of Adelaide, he became very active, joining the University Socialist Club, the Fabian Society, the Student Representative Council, as well as the Theatre Group. A two-week stint in the Communist Party was followed by membership in the Australian Labor Party.