Oeiras may refer to: Places Brazil Oeiras, Piauí, a municipality in the State of Piauí Oeiras do Pará, Pará, a municipality in the State of Pará Portugal Oeiras, Portugal, a municipality in the district of Lisbon Oeiras e São Julião da Barra, a former civil parish in the municipality of Oeiras Oeiras e São Julião da Barra, Paço de Arcos e Caxias, successor of the above