Horsham is a market town and civil parish in West Sussex, England, located on the upper reaches of the River Arun on the fringe of the Weald. It lies approximately 31 miles south-south-west of London, 18.5 miles north-west of Brighton, and 26 miles north-east of Chichester. Nearby towns include Crawley to the north-east and Haywards Heath and Burgess Hill to the south-east.
The town serves as the administrative centre of the Horsham district and had an estimated population of 50,934 in 2018. Its location within Sussex has made it a notable settlement in the region's geography and local governance.