Octávio Tarquínio de Sousa (7 September 1889 – 22 December 1959) was a Brazilian historian who wrote several works on the history of Brazil and some of its historical figures, such as emperor Pedro I, José Bonifácio and Diogo Antônio Feijó.

His most notable work was the compilation História dos Fundadores do Império do Brasil (History of the Founders of the Empire of Brazil) published in 1957.

He finished his secondary studies and joined the Faculty of Legal and Social Sciences of Rio de Janeiro, where he graduated with a law degree in 1907, beginning his career in the Postal Office administration and later joining the Postal Service of Rio de Janeiro from 1914 to 1918.

[1][2] Together with important Brazilian intellectuals who emerged in the 1930s, such as Gilberto Freyre, Caio Prado Júnior and Sérgio Buarque de Holanda, Tarquínio elaborated studies on Brazilian history, bringing new concepts to historiography and writing biographies about important historical Brazilian figures such as Bernardo Pereira de Vasconcelos, Evaristo da Veiga, Diogo Antônio Feijó, José Bonifácio and Pedro I.

[4][5] Tarquínio died in a plane crash in Rio de Janeiro on 22 December 1959, together with his wife Lucia Miguel Pereira (b.