Lord Castlereagh (disambiguation)

Lord Castlereagh may refer to:


 * Lord Castlereagh (1769–1822), Anglo-Irish politician
 * Marquess of Londonderry, courtesy title for heirs to the peerage
 * Lord Castlereagh (painting), an 1809 portrait by Thomas Lawrence
 * Lord Castlereagh (1802 ship), named after the politician
 * Lord Castlereagh (1803 ship), named after the politician