The Roman Catholic Diocese of Itaguaí () is located in the Ecclesiastical province of São Sebastião do Rio de Janeiro in Brazil.

History
14 March 1980: Established as Diocese of Itaguaí from the Diocese of Barra do Piraí–Volta Redonda and Diocese of Nova Iguaçu

Leadership
 Bishops of Itaguaí (Roman rite)
 Vital João Geraldo Wilderink, OCarm (1980.04.21 – 1998.07.08)
 José Ubiratan Lopes, OFMCap (1999.11.17 – present)

References
 GCatholic.org
 Catholic Hierarchy

Roman Catholic dioceses in Brazil
Christian organizations established in 1980
Itaguaí, Roman Catholic Diocese of
Roman Catholic dioceses and prelatures established in the 20th century