Gheorghe Grigore Cantacuzino, or Cantacuzino-Nababul (22 September 1833 – 22 March 1913), was a Romanian politician and lawyer, one of the leading Conservative Party policymakers. He twice served as the Prime Minister of Romania: between 23 April 1899 and 19 July 1900, and between 4 January 1906 and 24 March 1907. He resigned from office after failing to put down the large-scale peasants' revolt.
The immensely rich Gheorghe G. Cantacuzino was born into the aristocratic Cantacuzino family, of Phanariote origins. The Cantacuzino Palace of Bucharest and the Cantacuzino Castle of Bușteni were built by him. He was the father of Grigore Gheorghe Cantacuzino and Mihail G. Cantacuzino, as well as the father-in-law of Alexandrina Pallady-Cantacuzino.