Comunidade Intermunicipal do Oeste (Intermunicipal Community of the West; abbreviated OesteCIM) is an administrative division of Portugal, located on the country's western central coast. The population in 2011 was 362,540, in an area of 2,220.16 km². Caldas da Rainha serves as the seat of OesteCIM.
The law establishing the framework for intermunicipal communities and metropolitan areas was approved by the Assembly of the Republic (Assembleia da República) on 27 August 2008. On 25 November 2008, the Associação de Municípios do Oeste (Association of Municipalities of the West), by the approval of the municipal assemblies (assembleias municipais) of each of its constituent municipalities, converted itself into the Comunidade Intermunicipal do Oeste. The law formally establishing the names, borders, and duties of the intermunicipal communities and metropolitan areas was approved by the Assembly of the Republic on 12 September 2013.
OesteCIM is the successor to Associação de Municípios do Oeste (Association of Municipalities of the West) and Comunidade Urbana do Oeste (Urban Community of the West; abbreviated ComUrb Oeste), which had been instituted on 29 March 2004.
OesteCIM is coterminous with the statistical NUTS III subregion Oeste within the NUTS II Centro Region. It is a region famous for its fruits and vegetables production, namely the famous pêra rocha variety.