Arundel ( or ) is a market town and civil parish in a steep vale of the South Downs, West Sussex, England. It lies SSW of London, WNW of the English Channel town of Brighton, and east of the county town of Chichester. Larger nearby towns include Worthing, Littlehampton and Bognor Regis. The much-conserved town with large green buffers has a medieval castle and Roman Catholic cathedral. Although smaller in population than most other parishes, Arundel has a museum and comes second behind much larger Chichester in its number of listed buildings in West Sussex. The River Arun runs through the eastern side of the town.
Arundel was one of the boroughs reformed by the Municipal Reform Act 1835. From 1836-1889 the town had its own Borough police force with a strength of three. In 1974 it became part of the Arun district, and now is a civil parish with a town council.