Sybille, Baroness de Selys Longchamps (born August 28 1941) is a Belgian noblewoman. She is famous for being the mother of Delphine Boël, supposedly the illegitimate daughter of Albert II of Belgium, current King of the Belgians.

Born in Uccle, Belgium, she is the daughter of Count Michel François de Selys Longchamps and Countess Pauline Cornet de Ways-Ruart. In 1962, she married Jacques Boël, a well-known industrialist and nephew of René Boël. In 1968, Delphine Boël was born, allegedly from an extramarital affair with the Albert of the Belgium, not the king yet back then. The purported affair was made public in 1999.

See also

• Anne Pingeot, mother of Mazarine Pingeot, illegitimate daughter of François Mitterrand

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