Thomas Michael Slattery (17 December 1844 – 25 July 1920) was an Irish-born Australian politician.
He was born in Greenane in County Tipperary to shoemaker Edward Slattery and Alice Walsh. His family arrived in Sydney in 1847 and he attended St Mary's Seminary School before becoming a junior clerk in 1864. First working for the Customs Department, he clerked for the Supreme Court of New South Wales from 1872, becoming chief clerk in 1874. In 1875, he was admitted as a solicitor, practising first in the matrimonial courts and then from 1880 privately. On 10 January 1867 he married Annie Genevieve O'Connor, with whom he had four children. His second marriage, on 23 November 1886, was to Agnes Melvin O'Connor. In 1880 he was elected to the New South Wales Legislative Assembly as the member for Boorowa. He served in the Assembly until 1895, during which time he became associated with the Protectionist Party. He was twice Minister of Justice (1885, 1889), and also served as Secretary of Mines and Minister for Agriculture from 1891 to 1894. In 1900 he was appointed to the New South Wales Legislative Council, where he remained until 1905. He died in Mosman in 1920.