The Archdiocese of São Sebastião do Rio de Janeiro (Latin: Archidioecesis Sancti Sebastiani Fluminis Ianuarii, lit.

"Archdiocese of St. Sebastian of Rio de Janeiro") in Brazil was established as a territorial prelature on July 19, 1575.

On May 6, 2003, the territorial abbey of Nossa Senhora do Monserrate do Rio de Janeiro lost its territorial rank and was added to the archdiocese.

Cardinal Orani João Tempesta OCist has been its Archbishop since 2009.

Cardinal Eusébio Scheid SCI, who died on January 13, 2021, was Archbishop Emeritus.