Peterborough, (or Petersburg as it was known until 1918) was settled to service the agricultural and pastoral endeavours of the 1870s. A Mr William Heathersay was the first person to start a business venture up, when in 1878 he built a blacksmith shop. Several other ventures by other people soon followed. There are two theories as to how the town got its name. One is that it was named after Mr Peter Doecke, the original owner of the land on which the town was built. The other, that it was named after 'Peters Store', the first General Store in town.
The Railways; an Industry which would provide the lifeblood of the town for the next 110 years officially arrived in the town January 17, 1881 when the line from Jamestown opened. The Terowie line opened shortly after and the line to Broken Hill was opened in 1887 thus ensuring the future of the town. This meant that Port Pirie, Port Augusta, Adelaide and the Silverton Mines were all connected by rail tracks that passed through Peterborough. The town would forge ahead in leaps and bounds with the railways playing a major part in the development of it. In 1927 the workforce of the Peterborough Division of the South Australian Railways was 1800 with two thirds of them living in the town.
This was the era when the town experienced a boom in population and major building works. They included the Railway Roundhouse (largest in the southern hemisphere), Town Hall (largest in rural South Australia) and the imposing YMCA building.
Peterborough played a major part in the movement of the troops during the Second World War with troop trains moving north, south, east and west.
Unfortunately the railways has all but left the town but the assets and memories of that great steam era has been preserved at Steamtown which is situated in the original railway workshops at the western end of the town.
Over the last 8 years the local council has set aside money and utilised many Government Grants to improve the lifestyle and appearance of the town. As a result of this the town has won many awards in the statewide KESAB Tidy Towns Competition for its continued improvement and innovative approach.