Alter do Chão (European Portuguese pronunciation: [alˈtɛɾ ðu ˈʃɐ̃w] ⓘ) is a municipality in the District of Portalegre in Portugal.

[2] The present Mayor is Francisco Miranda, elected by a centre-right coalition of the Social Democratic Party and the People's Party.

The municipal holiday is Ascension Day.

The municipality is famous for its horsebreeding and high school of horseriding.

Administratively, the municipality is divided into 4 civil parishes (freguesias):[3]