The Roman Catholic Diocese of Itaguaí (Latin: Dioecesis Itaguaiensis) is located in the ecclesiastical province of São Sebastião do Rio de Janeiro in Brazil.

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

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

• GCatholic.org
• Catholic Hierarchy

22°52′09″S 43°46′43″W / 22.8692°S 43.7786°W / -22.8692; -43.7786