Slough is a town in Berkshire, England, in the Thames Valley 20 miles (32 km) west of central London and 19 miles (31 km) north-east of Reading, at the intersection of the M4, M40 and M25 motorways. It is part of the historic county of Buckinghamshire. In 2021 Census, the population of the town was 143,184. In 2021, the wider Borough of Slough had a population of 158,500. Slough borders the ceremonial counties of Greater London and Buckinghamshire.

The Royal County of Berkshire, commonly known as simply Berkshire, is a ceremonial county in South East England. It is bordered by Oxfordshire to the north, Buckinghamshire to the north-east, Greater London to the east, Surrey to the south-east, Hampshire to the south, and Wiltshire to the west. Reading is the largest settlement and the county town.