Sturt named the mountain in honour of Captain Barker after he was killed later that year by local Aboriginal people at the Murray Mouth.

Mount Barker township was surveyed in 1839 by Duncan McFarlane, who was hoping the area could be used for wheat and grain farming.

The land was divided into lots of 80 acres (32 ha), although farmers didn't settle until 1844, when John Dunn built the first steam flour mill outside of Adelaide.

[14] Mount Barker is famous as the place where the value of subterranean clover, Trifolium subterraneum as a fodder crop was discovered, proved and first promoted by A. W. Howard.

The discovery spread across Australia and to many other countries, due largely to Howard's generosity in publishing articles about clover, supplying seed free of charge around the world, and advising on handling.

It was growing in all Australian States, and requests for seed and information were being received in great numbers from almost all countries in the world with a temperate climate.

In 2003, largely due to concerns that Adelaide's urban sprawl was encroaching onto surrounding farmlands, the then State Planning Minister Jay Weatherill made a commitment to contain the expansion of Mount Barker.

[15] In 2008 a consortium of five developers sought the rezoning of 1,300 hectares (3,200 acres) of prime agricultural land in order to build an additional 7,700 new homes which would increase the population of Mount Barker from 10,258 to around 35,000.

The land included 40 hectares (99 acres) rezoned to light industry in order to provide jobs for the new population.

The following month Mark Parnell, the SA Greens representative in the South Australian Legislative Council made a request under the Freedom of Information Act 1991 for copies of documents passed between the developers and State Government.

[17][18][19][20][21][22][23] In December 2010, the State Government approved the rezoning, and development and construction began without the usual council infrastructure.

The council expressed concern that the reduction of the threat level would lead to a reduction of building standards compared to those standards required for homes in high risk areas and pointed out that the previous year, Victoria's Black Saturday bushfires Royal Commission had recommended that there should be less building in bushfire-prone areas.

[24][25] A new interchange on the South Eastern Freeway at Bald Hills Road has been built to improve travel times and road safety for commuters travelling to the east side of Mount Barker and reduce traffic congestion in Mount Barker.

The report found that the property consulting firm Connor Holmes "had a clear conflict of interest" that was known to Planning SA who took no action.

On 6 March 2013, SA Greens MP Mark Parnell gave notice he would introduce a motion to the Legislative Council to refer the matter to ICAC.

Mount Barker is at an elevation of 360 m. The city is just south of the freeway from Adelaide to Murray Bridge and Melbourne.

Mount Barker Central, also known as The Bilo Mall is the largest and oldest, containing a Coles, a Kmart and more than 50 speciality shops.

The Adelaide Hills Homemaker Centre replaced some old industrial buildings, previously Jacobs Smallgoods and Abattoir, near the St Francis de Sales College.

In 2023 the Aston Hills shopping center opened in the suburb of Aston Hills on the outskirts of Mount Barker, it is anchored by a Drakes supermarket furthermore in 2024 Woolworths Mount Barker South opened in a dedicated shopping center on the corner of Heysen Boulevard and the B37 road.

The Ukaria Cultural Centre, designed by architect Anton Johnson and built in 2015, is a leading venue for chamber music.

[36] Mount Barker has an independent weekly local newspaper which serves many Hills towns, The Courier, published on Wednesdays.

[38] Mount Barker has three ovals, the Mount Barker oval, right next to The Recreation Centre, where the Mount Barker Show is held, as well as local HFL footy matches, Dunn Park, which is located near Cornerstone College and the caravan park, although it is not used much any more and Summit Sport and Recreation Park; A large sports complex consisting of an AFL oval and grand stand and two soccer pitches and associated stands the main stand can hold approximately 250 persons and serves as also as a function center which can be hired by the general public.

Summit Sports and Recreation Park is noted for having held several matches of the AFL "Gather Round" during the 2023 and 2024 seasons.

[39] Mount Barker is home to the SteamRanger Heritage Railway which operates The Southern Encounter steam trains through Strathalbyn and Goolwa to Victor Harbor.

Mount Barker has a rugby league team, the Adelaide Hills Tigers, who compete in the NRL South Australia Metro competition.

Mt Barker hospital recently completed an upgrade of its emergency department to better suit the growing population.

In 2022 the South Australian Labor party pledged to expand the hospital, upon election funding was committed by the South Australian Labor Party and the hospital will undergo a substantial rebuild resulting in a multi story facility with a doubling of available bed space with a dedicated mental health wing also being on the agenda.

[46] As a result of rapid growth and traffic congestion on the South Eastern Freeway, sporadic calls have been made since the late 2010s to extend the former passenger rail service beyond Belair to Mount Barker.

However, a 2022 government-sponsored report rejected the prospect of opening a train service, arguing that reliability and travel time would "not come close" to buses and cars.

Overall about 1,500–2,000 students, from Mount Barker, as well as many of the surrounding towns, such as Nairne, Littlehampton and Strathalbyn, are serviced by these high schools.