Mario dei Principi Ruspoli (October 16, 1867 – January 16, 1963) was an Italian prince, son of Emanuele Ruspoli, 1st Prince of Poggio Suasa and first wife Princess Caterina Vogoride-Conachi.

[1] He was the 2nd Prince of Poggio Suasa and Prince of the Holy Roman Empire.

He was responsible for the brief development of Chatsworth, New Jersey as a resort in the early 20th century.

He married in Paris, September 25, 1890 Pauline Marie Palma de Talleyrand-Périgord (Venice, April 2, 1871 – Rome, October 21, 1952), daughter of the Maurice de Talleyrand-Périgord, the 4th Duke of Dino and Elizabeth Beers-Curtis (a sister of his father's third wife), and great-great-great-niece of Charles Maurice de Talleyrand-Périgord, by whom he had five children: