Castanheira de Pera (Portuguese pronunciation: [kɐʃtɐˈɲɐjɾɐ ðɨ ˈpeɾɐ]), often erroneously written Castanheira de Pêra, is a municipality in the district of Leiria in Portugal. The population in 2011 was 3,191, in an area of 66.77 km².

The present Mayor is Fernando José Pires Lopes, elected by the Socialist Party. The municipal holiday is on July 4.