O'Halloran was born in Berhampore India, the second of eight sons of Major-General Sir Joseph O'Halloran, by his wife, Frances, daughter of Colonel Nicholas Bayly, M.P., and niece of Henry, 1st Earl of Uxbridge. Thomas was a grandson of Irish surgeon Sylvester O'Halloran, and brother to William Littlejohn O'Halloran. O'Halloran entered the Royal Military College, Sandhurst in 1808 and at 16 he was commissioned into the 17th Foot and sailed for India. He served in the Nepal war during the years 1814, 1815, and 1816, became Lieutenant in June 1817, and served in the Deccan war during that and the following year. On 1 August 1821 he married Miss Anne Goss of Dawlish, Devonshire, who died in 1823 in Calcutta, leaving two children. In 1822 he exchanged from the 17th to the 44th Regiment, which he joined in Calcutta in January 1823. In 1824 he was ordered with the left wing of the 44th to Chittagong, where he arrived early in June, and was appointed paymaster, quartermaster, and interpreter. On 30 October he was appointed brigade-major to Brigadier-General Dunkin, C.B., who commanded the Sylket division of the army during the Burmese war, and served on his staff until his death in Nov. 1825. He received a medal for war service in India, for Nepal and Ava. O'Halloran transferred to the 99th Foot as a Captain in 1827. He returned to England after twenty years in India in 1834. On 10 July 1834 he married Miss Jane Waring, of Newry, County Down, and retired on half-pay in October of that year. Soon afterwards he transferred to the Coldstream Guards and was on half pay until he transferred again to the 97th Foot in May 1837.
South Australia
In 1838 O'Halloran retired from the army by the sale of his commission, and sailed for South Australia the same year with his wife Jane O'Halloran, their sons Thomas Joseph Shuldham and George Waring Wright and his daughter Annie Helen Lucy, in the Rajasthan, landing at Glenelg in November 1838. He established a farm, Lizard Lodge in the Adelaide suburb which now bears his name, O'Halloran Hill. He was made a J.P. in 1839. He was gazetted Major-Commandant of the South Australian Militia on 26 February 1840, and on 8 June as Commissioner of Police. In December 1839 he was appointed by George Gawler as one of four members of a Board of Police Commissioners. Upon the dismissal of the founder and first commander of the police, Superintendent Henry Inman in May 1840, the Board was abolished and O'Halloran was appointed under a new title of Police Commissioner. He retired from Government service in 1843 as a result of his disinclination to serve as both Police Commissioner and Police Magistrate.
''Maria'' controversy
In June 1840, the brig Maria set sail from Port Adelaide towards Hobart. By July 1840, stories and rumours had circulated that all 26 people on board had survived a shipwreck, but had been killed by members of the Milmenrura, a clan of the Tanganekald people, along the Coorong. After a police investigation, which discovered several mutilated bodies and determined who the murderers were believed to be, GovernorGawler ordered O'Halloran and Police InspectorAlexander Tolmer to lead a party of police and sailors to the area. His orders were to find and execute those responsible. On 22 August 1840, after several days of interviews, investigations and a drumhead court-martial, two Milmenrura men were publicly hanged on the Coorong in front of 65 people from their tribe. O'Halloran then told the people that their bodies were not to be taken down and that this was to be a warning against violence towards Europeans by Aboriginal people. This was one of the most contentious incidents in South Australian legal history. At the time, Aboriginals in South Australia were considered British subjects, and therefore deemed to be under the protection of British law. Gawler's ordering of a drumhead court-martial and the executions was not well received by the London authorities and contributed to his removal as governor. At that same time O'Halloran's younger brother, Captain Henry Dunn O'Halloran, 69th Regt., posted at New Brunswick, Canada, was conducting a significant study of the language and customs of the indigenous Mi'kmaq people.
Character
Although O'Halloran attracted a reputation for belligerence, one of his mounted troopers of the 1840s related that, "Old Major O'Halloran used to say 'I never hated a man longer than a day'".
Family
O'Halloran married Anne Goss on 1 August 1821; she had two daughters. He married again, on 10 July 1834, to Jane Waring; they had three sons and one daughter. His eldest son Thomas Joseph Shuldham O'Halloran SM, married Harriet Julia Woodforde, daughter of the Adelaide Coroner. Their son Thomas Shuldham O'Halloran KC was a noted lawyer and football administrator in South Australia. A daughter Eliza O'Halloran married farmer and flour miller Samuel White in 1853. O'Halloran died at his home "Lizard Lodge", and was buried at Christ Church, O'Halloran Hill, an Anglican church which he helped to establish and is also located in the suburb, now overlooking the former GlenthorneCSIRO Research station.
