The area now called Great Cornard has been occupied since pre-history, with evidence of Palaeolithic, Bronze Age and Roman settlements in the parish. The village is accounted for in the Domesday Book of 1086 as the manor Cornard.
The village was consistently a small one until the 20th century. Following the turn of the century the population steadily increased. In the 1950s and 60s the village was greatly expanded following the County of London Plan, with the village taking in London overspill. By the beginning of the 21st century the population of Great Cornard was approaching that of the town of Sudbury.