Sir Nicholas Roderick O'Conor GCB GCMG PC (Irish: Nioclás Ruairí Ó Conchobhair Donn; 1843 – 19 March 1908) was an Anglo-Irish diplomat.

He was raised on his family estate, Dun Dermot, on the Roscommon-County Galway border.

[4] He was Secretary and Chargé d'Affaires at Peking and Washington, Political Agent and Consul-General in Bulgaria.

1892, d. 22 March 1969), married her half first cousin, Rear-Admiral Malcolm Raphael Joseph Constable-Maxwell-Scott, son of Hon.

Youngest daughter: Eileen Winifred Madeleine O'Conor (1897-1963), married, in 1918, at the Brompton Oratory, to Romanian Prince Matyla Ghyka (1881–1965).