Colnbrook is a village in the Slough district in Berkshire, England. It lies within the historic boundaries of Buckinghamshire, and straddles two distributaries of the Colne, the Colne Brook and Wraysbury River. These two streams have their confluence just to the southeast of the village. Colnbrook is centred 3 miles (4.8 km) southeast of the Slough town centre, 4 miles (6.4 km) east of Windsor, and 19 miles (31 km) west of central London.

The Borough of Slough is a unitary authority with borough status in the ceremonial county of Berkshire, Southern England. The borough is centred around the town of Slough and includes Langley. It forms an urban area with parts of Buckinghamshire and extends to the villages of Burnham, Farnham Royal, George Green, and Iver. Part of the district's area was in Buckinghamshire prior to the district's formation and in Middlesex until 1965.