In 970 AD King Edgar established a monastery in Hardwick under Benedictine rule and gave it to Ealdorman Beorhtnorth. Ealdorman then gave the land amounting to 22 acres to the Abbot and convent of Ely in 991 AD in return for hospitality extended to his troops on route to fight the Danes at the Battle of Maldon with the request that, if he were to be killed in battle, Hardwick was one of the places where he would like to be buried. To this day the Bishop of Ely is Patron of St Mary's Church and appoints the rector.

Until the 11th century Hardwick was part of the settlement of Toft, a name of Scandinavian origin. Six teams of oxen and their handlers with 20 pigs were recorded as living in Hardwick at the time of the Domesday Book. The word means the settlement of shepherds, a sheep farm from the name meaning the place of the sheep, but the heavy clay soil used for the growing of oats in more modern times had led to the epithet "Hungry Hardwick".

There have been numerous spellings around the name of Hardwick over the centuries, the "e" only being dropped at the end of the Second World War.

In 1831 there were ten dwelling houses in the village, which was surrounded by three open fields, but at the time of enclosure in 1836 more were built and a new road linking the houses around the church with the main Cambridge to St Neot's road was built through to Toft. Previously the village green covered more than 10 acres and was surrounded by three open fields. Access to the outside world had been by the Portway (now also the Wimpole Way), an ancient track at the southern end of the village green linking Cambridge with Bedford and Wimpole Hall.

In 1836 the curate described Hardwick as "a very poor place and the people very ignorant", no doubt due to the fact that the village was almost inaccessible in wet weather.

Hardwick used to have two substantial homesteads. The Manor by a moat to the south east of the village was given to the monks of Ely and eventually endowed to Pembroke College to celebrate the completion of its chapel. Hardwick Hall lay to the west of the common land. Now the above ground signs of both are lost, Manor Crescent and Hall Drive being the only reminders.

Other than a few outlying farmhouses, poor communications on badly drained land hampered any development over the years until one-acre plots were given to Londoners and ex-soldiers after the First World War as part of the London Dockland Rehabilitation Scheme and a ribbon of bungalows was built along the St Neots Road in the 1930's, continued after the Second World War. Many of the post-war plots had become derelict and in the 1970's formed much of the site for 600 new houses on Limes Estate and Hardwick Park.

The first reference to a school was in 1580. There was a new school building in 1872. This church-owned village school was closed in 1968 and a new Community Primary School was opened in 1979.

From 11 people in 1086 Hardwick grew to 43 by the 13th century. The population was 81 adults in 1377 and fell to 14 families by 1563. From 158 in 1801 the numbers fell further to 90 in 10 dwellings in 1831, doubling by 1841 and rising to 248 in 1871, before declining again to 112 in 1901. The population stood at 471 in 1931. All small changes compared to a population of 470 in 1951 growing to 2,240 by 1986 and now likely to remain around 2,500.