| Consort: | yes |
| Alessandro Ruspoli | |
| Predecessor: | Prince Francesco Ruspoli |
| Successor: | Prince Francesco Ruspoli |
| Reign: | 1989–2005 |
| House: | Ruspoli |
| Father: | Prince Francesco Ruspoli |
| Mother: | Countess Claudia Matarazzo |
| Birth Date: | 9 December 1924 |
| Birth Place: | Rome, Kingdom of Italy |
| Death Place: | Rome, Italy |
Alessandro "Dado" Ruspoli, 9th Prince of Cerveteri (9 December 1924 – 11 January 2005) was an occasional actor and a playboy and eccentric aristocrat, the 9th Prince of Cerveteri, 9th Marquess of Riano, 14th Count of Vignanello and Prince of the Roman Papal States. Dado descends from a brother of Cardinal Bartolomeo Ruspoli.
Dado was born in Rome in 1924. His mother, his father's first wife Claudia dei Conti Matarazzo, who died when he was 9, was heiress to one of the largest fortunes in Brazil. His father Francesco Ruspoli, 8th Prince of Cerveteri, later a poet, fought in both World Wars. Dado became known for his extravagant lifestyle in the 1950s and 60s. He was friends with Brigitte Bardot, Salvador Dalí, Truman Capote, Roger Vadim, Roman Polanski, Emmanuelle Arsan and many others.
Ruspoli's first marriage, in Rome on 8 December 1947, was to Nobile Francesca dei Baroni Blanc (Rome, 27 June 1920 – Milan, 27 February 1962), daughter of Nobile Mario dei Baroni Blanc and wife Anita Felici. They had no children.
Ruspoli's second marriage at Vignanello, the location of the ancestral residence, Castello Ruspoli, on 5 May 1964, was to French aristocrat Nancy de Girard de Charbonnières (Pouillon, 18 April 1939 –), daughter of Roger Jean de Girard de Charbonnières and wife Andrée Marie Pommarède. The marriage produced one son:
Ruspoli's third marriage was also in Rome, on 20 November 1993, to Theresa Patricia Genest. This marriage produced a daughter and a son:
Between marriages Ruspoli had two sons by actress Debra Berger (17 March 1957 –), daughter of William Berger: