Oeiras is a Portuguese villa of the District of Lisbon, region of Lisbon and subregion of Great Lisbon, with near 34 800 inhabitants.
She is host of a small municipality with 45.75 km ² of area and 162 124 inhabitants (2001), subdivided in 10 freguesías. The municipality limits the north with the municipalities of Sintra and Amadora, to the east with Lisbon, the west with Cascais and the south has coast in the zone of the Tajo river, where the estuary finishes and begins the Atlantic Ocean, locating itself as opposed to Almada.
Concelho was created the 15 of April of 1760 by Jose I.