Voivode George Ducas (Greek: Γεώργιος Δούκας, Romanian: Gheorghe Duca) (d. 1685) was three times Prince of Moldavia (September 1665 – May 1666, November 1668 – 20 August 1672, November 1678 – January 1684) and one time Prince of Wallachia (1673 – 29 November 1678).He was married to Anastasia, the daughter of Eustratie Dabija, and later to Dafina Doamna; George Ducas fathered Constantine Ducas.