Corinium Dobunnorum was the Romano-British settlement at Cirencester in the present-day English county of Gloucestershire. Its 2nd-century walls enclosed the second-largest area of a city in Roman Britain. It was the tribal capital of the Dobunni and is usually thought to have been the capital of the Diocletian-era province of Britannia Prima.

Cirencester is a market town in Gloucestershire, England, 80 miles (130 km) west of London. Cirencester lies on the River Churn, a tributary of the River Thames. It is the eighth largest settlement in Gloucestershire and the largest town within the Cotswolds. It is the home of the Royal Agricultural University, the oldest agricultural college in the English-speaking world, founded in 1840. The town had a population of 20,229 in 2021.