Orroroo is a town in the Yorke and Mid North region of South Australia. At the 2016 census, the locality of Orroroo had a population of 610 while its urban centre had a population of 537. The Wilmington-Ucolta Road passes through here, intersecting with the RM Williams Way which leads to the Birdsville and Oodnadatta Tracks. The Peterborough–Quorn railway line extended from Peterborough to Orroroo also in 1881 and Quorn in 1882, connecting with the new Central Australia Railway from Port Augusta. These railways have now been abandoned. Orroroo is situated near Goyder's Line, a line drawn up in 1865 by Surveyor General Goyder which he believed indicated the edge of the area suitable for agriculture.

Prior to European settlement, Orroroo was the home of the Ngadjuri Aboriginal people whose domain was the area to the east of the Flinders Rangers. The name Orroroo was thought to be a form of onomatopoeia in imitation of wind blowing through acacia trees. According to J. Gray, it actually meant 'early start', referring to the fact that the Ngadjuri, who usually camped at Pekina Creek, would move to camp at the Orroroo river the night before hunting for kangaroos, which would come up to the river at that point and thus allow them to make an early start at dawn for the hunt. Aboriginal origins, but the true meaning of the word is uncertain. The name was first used by an early pioneer who conducted a nearby coaching house which served travellers on the Burra-Blinman track.

In 1844, the first Europeans to settle, John and James Chambers, took up the Pekina Run which covered 320 square miles. They did not receive any rain during the 17 months that they lived there. As a result of this drought, they sold the Pekina Run for £30.

Charlie Easther settled in Orroroo during 1864 and opened up an eating house that became a popular stopping point for the drovers and bullockies who travelled through the area. The town was surveyed in 1875, when Solly's Hut, a clay-pugged log structure, was constructed as the town's first house and is now used as a museum. In September 1875, the town was officially named by George Goyder following the suggestion made by Charlie Easther . The first land sales were made in May 1876. The town was granted its own local council, the District Council of Orroroo, in 1887 (taking effect in 1888), and the town's council offices were constructed in 1888. The District Council of Orroroo would survive until 1997, when it was merged to create the District Council of Orroroo Carrieton.

On 24 August 1923, 230-volt electricity was connected to the town by Cr Martin Redden, Chairman of the District Council, in the presence of a large crowd. On 4 July 1962, the power house engines were shut down and the town was connected to the ETSA 240-volt grid.

An early irrigation scheme was formed after damming the Pekina Creek and creating the Pekina reservoir. Water from here was supplied to over 50 dairy farms. Orroroo had its own flour mill, several bakeries, carriage manufacturer and a butter factory, which still stands.

Orroroo is the service centre for a predominantly farming community with the main products being wheat, sheep, cattle, pigs and a kangaroo processor.

A local curiosity is nearby, called "Magnetic Hill", which is a gravity hill optical illusion.