Metropolitan Cathedral of St. John the Baptist, Niterói, Catholic cathedral in Jardim São João, Niterói, Brazil.

The Metropolitan Cathedral of St. John the Baptist is a Catholic church in Jardim São João, in the historic centre of Niterói. It has two bell towers and a late colonial design. Inside, the nave was decorated in 1929 by the Italian artist Colossi, and the high altar was consecrated in 1942.

The cathedral's origins trace to 1819 with the founding of Royal Ville of Praia Grande, and it received a land donation in 1821 from the Brotherhood of St. John the Baptist. This gift established the foundation for the site's development as a religious and civic center.

The cathedral is home to the Irmandade de São João Batista, founded in 1742 and now the Irmandade do Santíssimo Sacramento. The patron saint's image, moved in 1744 after the chapel choir collapsed, is still venerated here. The church was consecrated as a cathedral in 1908 by Bishop Dom Agostinho Francisco Benassi.

The cathedral sits near the historical center of Niterói and welcomes visitors interested in exploring its architectural features. It remains active with religious services, so visiting during quieter times allows better observation of the space.

The cathedral's organ was built by Guilherme Berner and inaugurated on 22 June 1947. The church was shelled during the Naval Revolt of 1891–1894, and its interior was decorated in 1929 by the Italian artist Colossi for a budget of 120 contos de réis.