Orsett Rural District was a local government district centred on Orsett in the south Essex part of the Thames Estuary in England. It was a rural district from 1894 to 1936, initially made up of seventeen civil parishes and the successor to the Orsett Rural Sanitary District. Parts of the district were split off to form Tilbury in 1912, Purfleet in 1929 and Billericay in 1934. Thurrock Urban District was the main successor district in 1936. Today it corresponds to the Thurrock unitary authority area with parts in Basildon, Essex and Havering, Greater London.
In 1902 the parish council of Chadwell St Mary made a request to be converted into an urban district council.[4] Three schemes were considered at an inquiry in 1912: conversion of Chadwell St Mary parish to an urban district, amalgamation of Chadwell St Mary and Little Thurrock as a new urban district, and expansion of Grays Urban District to include Chadwell St Mary, Little Thurrock, West Thurrock and part of Stifford.[5] Following the inquiry, the Chadwell St Mary parish was removed from the rural district in 1912 to form the Tilbury Urban District.[6]
In 1929 Purfleet Urban District was formed from the parishes of Aveley, South Ockendon and West Thurrock.[7]