Before the Romans and Saxons were present, there was a Celtic settlement in the area, with evidence of a hill fort in the Pollards Hill area. The discovery of Roman-era graves and a well on the site of the Mitcham gas works evince Roman settlement. The Saxon graveyard, located on the North bank of the Wandle is the largest discovered to date, and many of the finds therein are on display in the British Museum. The area is a possible location for the Battle of Merton, 871, in which King Ethelred of Wessex was either mortally wounded or killed outright. The Church of England parish church of St Peter and St Paul dates from the Saxon era. Although it was mostly rebuilt in 1819–21, the current building retains the original Saxon tower. The Domesday Book of 1086 lists Mitcham as Michelham, a small farming community, with 250 people living in two hamlets; Mitcham, an area known today as Upper Mitcham; and Whitford, today known as the Lower Green area.
During her reign Queen Elizabeth I made at least five visits to the area. John Donne and Sir Walter Raleigh also had residences here in this era. It was at this time that Mitcham became gentrified, as due to the abundance of lavender fields, Mitcham became renowned for its soothing air. The air also led people to settle in the area during times of plague.
There were many lavender fields in Mitcham, and peppermint and lavender oils were also distilled. In 1749 two local physic gardeners, John Potter and William Moore, founded a company to make and market toiletries made from locally-grown herbs and flowers. Lavender features on Merton Council's coat of arms and the badge of the local football team, Tooting & Mitcham United F.C., as well as in the name of a local council ward, Lavender Field.
Mitcham was industrialised first along the banks of the Wandle, where snuff, copper, flour, iron and dye were all worked. Mitcham, along with nearby Merton Abbey, became the calico cloth printing centres of England by 1750. Asprey, suppliers of luxury goods made from various materials, was founded in Mitcham as a silk-printing business in 1781. William Morris opened a factory on the River Wandle at Merton Abbey. Merton Abbey Mills were the Liberty silk-printing works. It is now a craft village and its waterwheel has been preserved.
The activity along the Wandle led to the building of the Surrey Iron Railway, the world's first public railway, in 1803. The decline and failure of the railway in the 1840s also heralded a change in industry, as horticulture gradually gave way to manufacturing, with paint, varnish, linoleum and firework manufacturers moving into the area. The work provided and migratory patterns eventually resulted in a doubling of the population between the years 1900 and 1910.
Mitcham train station opened on 22 October 1855. The route was operated as a conventional railway until it was closed by Railtrack on 31 May 1997, for conversion to tram operation. Station Court, on the north of the tram line and east of London Road A217, was one of the SIR's original station buildings, used as a merchant's home, making it one of the oldest railway buildings in the world. The wall of the Ram Brewery on York Road has a plaque commemorating this.
Social housing schemes in the 1930s included New Close, aimed at housing people made homeless by a factory explosion in 1933 and Sunshine Way, for housing the poor from inner London. This industry made Mitcham a target for German bombing during World War II. During this time Mitcham also returned to its agricultural roots, with Mitcham Common being farmed to help with the war effort.
Post war, the areas of Eastfields, Phipps Bridge and Pollards Hill were rebuilt to provide cheaper more affordable housing. The largest council housing project in Mitcham is Phipps Bridge estate. Further expansion of the housing estates in Eastfields, Phipps Bridge and Pollards Hill occurred after 1965. In Mitcham Cricket Green, the area lays reasonable, although not definitive, claim to having the world's oldest cricket ground in continual use, and the world's oldest club in Mitcham Cricket Club.