Rio Branco was born in Salvador, in what was then the Captaincy of Bahia, to a wealthy family, but most of the fortune was lost after his parents' deaths early in his childhood.
Rio Branco lahir di Salvador, Kekaptenan Bahia, dari sebuah keluarga kaya, namun kehilangan kekayaannya setelah kematian orangtuanya pada awal masa kecilnya.