Rainham is a town in the unitary authority area of Medway, in the ceremonial county of Kent, England. The town forms a conurbation with neighbouring towns Chatham, Rochester, Strood and Gillingham. Historically, Rainham was a separate village. In 1921 the civil parish had a population of 4335. On 1 April 1929 the parish was abolished and merged with Gillingham and became part of the Municipal Borough of Gillingham, which was originally created in 1903 and was grouped into the latter's built-up area in analysis of the 2011 census by the Office for National Statistics. It became part of the Medway authority when Gillingham was incorporated with the other towns to form Medway Unitary Authority in 1998. It is now in the unparished area of Gillingham.
Population: 34,088 (2011 census, Rainham North, Central and South wards)