João was born in Boulogne-Billancourt, France to Pedro de Alcântara, Prince of Grão-Pará and Countess Elisabeth Dobržensky de Dobrženicz. His father had been a member of the Brazilian Imperial Family but had joined his mother Isabel, Princess Imperial of Brazil in exile after the abolition of the monarchy.
When João was 19, he emigrated to Brazil. In 1938 he was injured in the Levante integralista, an attempt to storm the Palácio Guanabara, the residence of President Getúlio Vargas. During World War II, João served in the Brazilian Air Force, flying Catalina flying boats.
After the War, he was vice president of Pan-Air do Brasil. João retired to Paraty on the west coast of the state of Rio de Janeiro. He died at the age of 88 in Rio de Janeiro.
As a young man he was a member of Ação Integralista Brasileira (AIB), a Fascist group led by writer Plínio Salgado.
