(5 July 1952 - 9 April 1963) (her death) (1 child)
M1. Alexander
His third wife, whom he married in 1952, was Charlene Stafford Wrightsman (1927–1963), the younger daughter of Charles B. Wrightsman, an oil millionaire whose collection of French and Austrian furniture — much of which was acquired through the designers Denning & Fourcade — and decorative arts fills several galleries at the Metropolitan Museum. She was previously married (1947–1950) to the actor Helmut Dantine, by whom she had a son, Dana Wrightsman Dantine. She and Cassini had one son, Alexander.
On April 8, 1963, while in her bedroom, with her 14-year-old stepdaughter, Marina Cassini, by her side, as the teenager watched the 35th Academy Awards on television, Charlene Cassini swallowed 30 sleeping pills and died the next day. She reportedly was distraught after Attorney General Robert F. Kennedy had indicted her husband for failing to register under the U.S. Registration Act, as an agent of a foreign government (a public relations agency he helped found, Martial & Company, had taken on the Dominican Republic as a client). She also suffered from headaches following a minor household accident, was depressed after the suicide of a ski instructor friend, and had become bitterly estranged from her father.
After his wife's death, Cassini later wrote, "We discovered the apartment, particularly her closets, littered with all kinds of pills, hidden in vases, under linens, stuffed in her shoes and the pockets of her clothes."