- Type: Yacht
- Displacement: 2,250 tons
- Dimensions: 325 x 36.5 x 14 ft.
- Machinery: 2 MAN diesels, 5,550 bhp = 19 knots
- Passengers: 36
- Crew: 34
- Builder: Canadian Vickers Ltd, Montreal, Quebec, Canada, 1943
- Service: Built as Canadian frigate HMCS Stormont of the River class. Bought by shipping magnate Aristotle Onassis in 1954. Converted at the cost of $4 million and named Christina after his daughter. Served as his floating home from 1954 to 1975. During that time the yacht hosted many luminaries, including Marilyn Monroe, Frank Sinatra, Maria Callas, and King Farouk of Egypt. John F. Kennedy first met Winston Churchill aboard the yacht, and two celebrated wedding receptions were held on board: Prince Rainier of Monaco to Grace Kelly, and Onassis himself to Jacqueline Kennedy. After his death in 1975, his daughter donated the ship to the Greek government. Purchased in 1998 by John Paul Papanicolaou, an Onassis family friend and shipping industry leader, the yacht underwent a three-year $54 million renovation and was rechristened Christina O. She is now available for private charter.