The Roman Catholic Diocese of São Mateus () is a diocese located in the city of São Mateus in the ecclesiastical province of Vitória in Brazil.

History 16 February 1958: Established as Diocese of São Mateus from the Diocese of Espírito Santo

Leadership Bishops of São Mateus (Roman rite) Bishop José Dalvit, M.C.C.I. (1959.05.09 – 1970.05.14) Bishop Aldo Gerna, M.C.C.I. (1971.05.18 – 2007.10.03) Bishop Zanoni Demettino Castro (2007.10.03 – 2014.12.03) Bishop Paulo Bosi Dal'Bó (2015.10.21 – present)

References GCatholic.org Catholic Hierarchy Diocese website (Portuguese)