He died in Boulogne-Billancourt, France in 1981 and his ashes are buried at the Cimetiere de Trivaux in Meudon France,next to his wife Princess Bouaphanh na Champassak (b. 1920- d. 2013).
Prince Souphanouvong (July 13, 1909 — January 9, 1995) was, along with his half-brother Prince Souvanna Phouma and Prince Boun Oum of Champasak, one of the “Three Princes” who represented respectively the communist (pro-Vietnam), neutralist, and royalist political factions in Laos.