Rainham is a town in the unitary authority of Medway, in Kent, South East England. The town forms a conurbation with neighbouring towns Chatham, Rochester, Strood and Gillingham.
Historically, Rainham was a separate village until, in 1928, it was added to 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.