Daughter of Clarence Dillon, Dorothy Dillon like her cousin, Seymour Weller, had strong ties with France. Raised with a French Mademoiselle, she learned to speak French as a child. She often accompanied her parents to France and discovered Haut-Brion at the onset of the Dillon family ownership.

In the nineteen fifties she studied for a P.H.D. at Columbia University. This permitted her to pursue her interests in mathematics and astronomy. She came often to Chateau Haut-Brion and was on the Board of Directors throughout her 85th year.

Dorothy Dillon died on June 8, 2005. Her children and grandchildren remain on the Board of Domaine Clarence Dillon.