Born in Espírito Santo do Pinhal, Sebastião da Silveira Cintra studied at the seminary in São Paulo and the Pontifical Gregorian University in Rome before being ordained to the priesthood on October 28, 1904.

He then did pastoral work in the Archdiocese of São Paulo, including serving as a seminary professor and the director of the archdiocesan newspaper A Gazeta do Povo.

He received his episcopal consecration on the following June 24 from Joaquim Arcoverde de Albuquerque Cavalcanti, with Archbishop Francisco do Rego Maia and Bishop Juan Terrero y Escalada serving as co-consecrators, in Rome.

Cintra eventually succeeded Cardinal Arcoverde as Archbishop of São Sebastião do Rio de Janeiro upon the latter's death on April 18, 1930.

Also in 1930, in November, he intervened in the revolution through which Getúlio Vargas assumed power:[1] The Cardinal was credited with saving the life of the incumbent president, Washington Luís.