Saint Peter Cathedral, Roman Catholic Cathedral in Rio Grande, Brazil

Saint Peter Cathedral is the seat of the Diocese of Rio Grande, in Rio Grande, Rio Grande do Sul, Brazil. Construction began in 1755 on a design by José Fernandes Alpoim in a late Baroque style, ordered by Gomes Freire de Andrade. It measures 17 m wide by 28.5 m long, with a single nave and a chancel; the exterior decoration is minimal apart from the framed stone doorway, while the interior holds nine carved altars, the main one dedicated to Saint Peter.

The church was built during the colonial era under Portuguese rule and has been the city's main religious building ever since. In 1938, Brazil's national heritage authority IPHAN gave it official protection as a listed monument.

The cathedral is the seat of the Diocese of Rio Grande and became a cathedral in 1972. Its nine carved altars include the main one dedicated to Saint Peter, and the collection holds illuminated manuscripts, sacred vestments, ceramics, porcelain and faience, plus pieces donated by emperors Dom Pedro I and Dom Pedro II, who each visited twice.

The cathedral is in the center of Rio Grande and easy to reach on foot from the main square. As an active place of worship, modest clothing covering shoulders and knees is appropriate, and checking opening hours before visiting is a good idea.

The cathedral holds pieces donated by emperors Dom Pedro I and Dom Pedro II, each of whom visited it twice. Its collection also includes illuminated manuscripts, sacred vestments, ceramics, porcelain and faience, alongside bronze candelabra, crystal chandeliers and oil paintings noted by Athos Damasceno.