Luiz Gastão Maria José Pio de Orléans e Bragança (6 June 1938 – 15 July 2022), known as Dom Luiz de Orléans e Bragança, was the head of the Petrópolis branch of the House of Orléans-Braganza and a claimant to the defunct Brazilian throne. He was the eldest son of Pedro Henrique of Orléans-Braganza and Princess Maria Elisabeth of Bavaria.
Born in Mandelieu-la-Napoule, France, he moved to Brazil with his family in 1945. He studied at the Colégio Santo Inácio in Rio de Janeiro and later earned a degree in Chemical Engineering from the Polytechnic School of the University of São Paulo (USP) in 1961. He worked as an engineer for several years before dedicating himself fully to dynastic activities and monarchist advocacy.
Upon the death of his father in 1981, he became the head of the Petrópolis line of the Brazilian Imperial House, styling himself "Prince Imperial of Brazil." His claim was contested by the Vassouras branch, headed by his cousin Prince Pedro Carlos of Orléans-Braganza (and later Prince Bertrand of Orléans-Braganza), due to a dynastic dispute originating from the 1908 renunciation of his grandfather, Pedro de Alcântara, Prince of Grão-Pará, which the Petrópolis branch considered invalid under Brazilian monarchical law.
Luiz of Orléans-Braganza was a prominent figure in Brazilian monarchist movements. He authored several books and articles on Brazilian history, politics, and the monarchy, including Brasil: A Última Esperança (Brazil: The Last Hope) and A Viabilidade do Reino (The Viability of the Kingdom). He advocated for a parliamentary constitutional monarchy and participated in the 1993 plebiscite campaign on the form of government, where the monarchist option received approximately 10% of the vote.
He never married and had no children. Upon his death in São Paulo on 15 July 2022, the headship of the Petrópolis branch passed to his brother, Bertrand of Orléans-Braganza.
