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.

A market town is a settlement most common in Europe that obtained by custom or royal charter, in the Middle Ages, a market right, which allowed it to host a regular market; this distinguished it from a village or city. In Britain, small rural towns with a hinterland of villages are still commonly called market towns, as sometimes reflected in their names.