Robert Campbell (5 October 1804 – 30 March 1859) was an early opponent of penal transportation and an Australian politician, Colonial Treasurer of New South Wales. He was also an elected as a member of the New South Wales Legislative Assembly and later, the New South Wales Legislative Assembly.
Campbell was the second son of Robert Campbell and born at Campbell's Wharf, The Rocks in Sydney, Australia. In 1810, his parents sent him to Pimlico, London, England to be educated and he returned in 1819.
In 1827 Campbell joined his father's company Campbell and Co. In 1829 he became active in the anti-transportation campaign. In the early 1830s, he refused to sit on a jury that included emancipists in order to draw attention to this cause and as a result became the leader of the campaign. In 1835 he had married Annie Sophia, daughter of Edward Riley (1784-1825), a merchant and pastoralist in the Sydney area.
In response to an 1846 parliamentary committee recommendation that transportation (which had ceased in 1840) be recommenced, Campbell organized a protest meeting. A petition in opposition to transportation was signed by some 6800 persons was presented to the Legislative Council and the British Government. Nevertheless, the convict ship, the Hashemy, arrived in 1849, but further meetings chaired by Campbell prevented more convicts being sent to Sydney.
In 1851 Robert was elected to the Legislative Council representing the City of Sydney. In 1856 he was elected to the first Legislative Assembly. He was Colonial Treasurer from August to October 1856 and from January 1858 until his death. He became ill and died at his father's property at Duntroon in what is now Canberra. His daughter was married to Edward Wolstenholme Ward.