Portslade is a western suburb of the city of Brighton and Hove in the ceremonial county of East Sussex, England. Portslade Village, the original settlement a mile inland to the north, was built up in the 16th century. The arrival of the railway from Brighton in 1840 encouraged rapid development of the coastal area and in 1898 the southern part, formerly known as Copperas Gap, was granted urban district status and renamed Portslade-by-Sea, making it distinct from Portslade Village. After World War II the district of Mile Oak to the north was added. Today, Portslade is bisected from east to west by the old A27 road between Brighton and Worthing, each part having a distinct character.

The Adur is a river in Sussex, England; it gives its name to the Adur district of West Sussex. The river, which is 20 miles (32 km) long, was once navigable for large vessels up as far as Steyning, where there was a large Saxon port, but by the 11th century the lower river became silted up and the port moved down to the deeper waters at the mouth of the river in Shoreham-by-Sea.