Area: 41.76 kmē 

Southend-on-Sea is a seaside resort and unitary authority in the East of England. The borough of Southend-on-Sea is part of the ceremonial county of Essex and is located on the north side of the Thames estuary roughly 40 miles (65 km) east of London. It is bordered to the north by Rochford and to the west by Castle Point. Southend is twinned with the Polish seaside resort of Sopot.

Originally the south end of the village of Prittlewell, Southend became a popular seaside resort for Londoners during the Victorian era. Owing to its proximity to London and easy access by train, the town's economy has largely been based on tourism ever since. Southend Pier is the world's longest pleasure pier at 1.34 miles (2158 metres). Over the years the pier has suffered fires and ship collisions, most recently in October 2005, but it has been repaired each time.

With the decline of traditional British sea-side resorts, from the 1960s onwards much of the centre of Southend was developed as a centre of commerce, and many of the original features of this once-attractive Victorian seaside town were destroyed through redevelopment or neglect. Her Majesty's Revenue and Customs, formerly Customs and Excise, are major employers in the town, and the central offices for the collection of VAT are located there. Southend recently opened its new university aimed at boosting the town's flagging economy. Many Southend residents commute into London, which may account for the town's entertainment and cultural attractions being relatively under-developed, compared to towns of a similar population and demographic composition.