Palácio Duque de Caxias, Military headquarters building in Centro, Rio de Janeiro, Brazil.

Palácio Duque de Caxias is a military command building located in downtown Rio de Janeiro, featuring red and black granite exteriors with polished Brazilian marble flooring throughout. The structure rises across multiple levels and serves as headquarters for military administrative operations across different branches.

The palace was built on the site of the 19th-century General Headquarters of Praça da República, which had housed the Ministry of War. Designed by Christiano Stockler das Neves and José Ferreira Louro in reinforced concrete, it opened in 1941 with Avenida Presidente Vargas. It served as the Ministry of War while Rio de Janeiro was Brazil's capital, until 1960. In 1953 the Pantheon Duque de Caxias, with an equestrian statue of the Army's patron, was inaugurated in front of it.

The building's name honours Luís Alves de Lima e Silva, the Duke of Caxias, patron of the Brazilian Army. In front of the palace stands the Pantheon Duque de Caxias, inaugurated in 1953, with an equestrian statue of the duke; the site is used for army ceremonies. The palace is listed as cultural heritage by INEPAC.

The building is centrally located in downtown Rio de Janeiro but is generally not open to visitors without special authorization, as it remains an active military headquarters. Those interested in tours should inquire about access possibilities in advance.

The equestrian statue in front of the palace is the Panteão Duque de Caxias, inaugurated in 1953 in honour of Luís Alves de Lima e Silva, the Duke of Caxias and patron of the Brazilian Army. The palace itself stands on the site of the 19th-century General Headquarters of Praça da República, and it has been listed by INEPAC.