The Hallett area has been settled since the early 1840s. It was named after John Hallett, as were Hallett Cove, the Hundred of Hallett and the District Council of Hallett. His brother Alfred was owner of Wandilla station, (Aboriginal name Willogoleeche). John first had land near Hallett Cove and Alfred managed the Bremer mine.
John Hallett later moved north and had a station in the Hallett area and by 1845 held 160 square miles of pastoral land on Occupation Licence no 18. After the death of both brothers, the land was sold at auction with most of it bought by E. Bowman. The Bowmans leased and owned much of the land including the Mount Bryan Estate.
After the pastoralists came the farmers who with the passing of the Strangways Act in 1869 were able to take up land on credit. The town of Hallett was surveyed and town lots were first offered for sale on 7 July 1870. Population at first remained small and the local school had to be closed for want of a teacher on 12 May 1874.
Eventually more and more people settled in the town and neighbourhood and John Tiver advertised in 1878 as Wine, spirit, and general storekeeper. He notified his numerous friends and the general public that he was now prepared to supply at the lowest possible rates the very best brands at his Hallett store. He also bought and stored wheat and would lend bags. He always had bran, pollard, hay and chaff on hand and would pay the highest prices for dairy produce.
Not to be outdone, James Russell, carpenter, builder and undertaker advertised in November 1878 that he had Timber, Iron, and Building materials of every description on sale. D.C. Worrell, Carpenter, wheelwright etc, advertised in December 1878 that Woodwork of all descriptions in the above line would be done at reasonable prices and with quick dispatch. M. Lambs and E. Tangye, Carpenters and Builders would erect Weatherboard or Iron Houses at the very shortest notice at the lowest current rate.
At a meeting, held on 7 October 1878, the District Council of Hallett called for tenders for the laying out of a cemetery. Hallett residents were proud of their cemetery where the council had planted 150 trees as early as 1877. Many residents from nearby Mount Bryan East, Ulooloo and other localities also found their last resting place at it.
The township of Hallett made considerable progress. Among some of the additions was a very neat and suitable public school. It was also intended to build an Institute to 'benefit those who are older in years or who have sufficient energy to enter upon a course of self-improvement'. Mr Smith of the Telegraph station had pushed for it. An entertainment, held at Mr Tiver's wheat store on 11 April 1879, provided some of the funds needed. The Hallett races on 3 June 1879 also provided some funds for this project.
Hallett eating house adjoining Crittenden's Booking Office for the Jamestown Coaches. John Blight was well established by 1879 and kept his well-known eating house and refreshment rooms and was glad to welcome both old friends and new ones. Tea Coffee and other refreshments were always ready and a good meal could be had for one shilling and sixpence.
A start was made with a Post Office and Telegraph Station in June 1879. The foundation stone for the Institute was laid on 6 August at 2.30 pm. by Rowland Rees, MP. and followed by a public tea meeting.
With the increase of gold mining around Hallett, some residents financed a small party to dig at Ulooloo in July 1879.
E.F. Opie was District Clerk in 1886 and F.S. Smith secretary of the Institute. The Institute now had 441 books in its library. The average daily attendance in its reading room was six with a total attendance for the year of 1860. It also had several newspapers and periodicals. They included the South Australian Advertiser, South Australian Times, Burra Record, Jamestown Review, South Australian Government gazette, Australian Sketcher and the London Graphic.
During 1886, Hallett was struck by gold fever. Several men have gone to the Teetulpa diggings and others are preparing. Miner's Rights were issued to Samuel Collins, Charles Edwards and John and Henry Rosewall in December 1886. The Institute sports had to be postponed owing to the rush to the Teetulpa Goldfields, from 9 November till the Christmas Holidays. The local butcher had sold his business to Mr Gillespie of Whyte-Yarcowie and also gone to the diggings. The blacksmith and wheelwright followed the crowd in November 1886.
In 1895 Mary Ann Worrell was appointed Poundkeeper in place of Donald McDonald. John Bernard Taylor, Head Teacher at Hallett, died on 18 February 1895. By this time the Hallett School had an average attendance of 52 students. Matthew C. Mitchell was teaching at 180 Pounds per annum in 1898. In 1900 Peter Garibaldi Doig was appointed to the school at 170 Pounds and he also became a member of School Board of Advice.
In 1906 the town had a population of 250. It had increased to 484 by 1936.