The Brazilian monitor Alagoas was the third ship of the Pará-class river monitors built for the Imperial Brazilian Navy during the Paraguayan War in the late 1860s. Alagoas participated in the Passage of Humaitá on 19 February 1868 and provided fire support for the army for the rest of the war. The ship was assigned to the Upper Uruguay (Portuguese: Alto Uruguai) flotilla after the war. Alagoas was transferred to Rio de Janeiro in the 1890s and participated in the Navy Revolt of 1893–94. The ship was scrapped in 1900.