Brazilian ironclad Rio de Janeiro
 The Brazilian ironclad Rio de Janeiro was an armored gunboat (Portuguese: Canhoneira Couraçada Nr. 3) built for the Brazilian Navy during the Paraguayan War in the mid-1860s. Like the other two gunboats she was built in Brazil and was designed as a casemate ironclad. Commissioned in April 1866 the ship did not enter combat until September when she bombarded Paraguayan fortifications at Curuzu. Rio de Janeiro hit two mines on 2 September and rapidly sank taking 53 of her crew with her.