Castlereagh

• Castlerea
• Castlereagh (County Down barony)
• Castlereagh (County Down townland)
• Castlereagh (County Roscommon barony)
• Castlereagh (County Roscommon townland)
• Castlereagh (borough)
• Castlereagh Highway
• Castlereagh Lower
• Castlereagh River
• Castlereagh Street
• Castlereagh Upper
• Castlereagh, Clanmorris
• Castlereagh, County Offaly
• Castlereagh, County Waterford
• Castlereagh, New South Wales
• Castlereagh, Nova Scotia
• Castlereagh, Tirawley
• Castlereigh Dam
• List of townlands of County Offaly
• List of townlands of County Roscommon
• List of townlands of County Waterford
• Marquess of Londonderry
• Nuwara Eliya
• Robert Stewart, Viscount Castlereagh
• The Castlereagh (Gilgandra)