Charles Gabriel Marie Sosthène II de La Rochefoucauld (1 September 1825 – 27 August 1908), 4th Duke of Doudeauville, 1st Duke of Bisaccia, Grandee of Spain, was a French politician during the Third Republic who served as Deputy for Sarthe from 1871 to 1898 and French Ambassador to London from 1873 to 1874.

[3] His aunt, Françoise Charlotte Ernestine de La Rochfoucauld, was the wife of Pierre Jean Julie Chapt, Marquis of Rastignac.

He was created Duke of Bisaccia (second creation) on 16 May 1851 by King Ferdinand II in the peerage of the Kingdom of the Two Sicilies, through his mother's family, the Montmorency-Lavals.

After his father died at the family's Château d'Armainvilliers in 1864, his elder brother succeeded to the dukedom of Doudeauville.

He hired French architect Henri Parent to renovate the Hôtel by putting up panelling (originally in the Château de Bercy) and creating a chapel, a winter garden, a dining room, stables for 25 horses, two rooms for eight carriages, two cellars and a grand staircase ("escalier d'honneur") panelled with polychromatic marble plaques that was inspired by the Queen's staircase at the Palace of Versailles.

He was also the owner of Vallée-aux-Loups ("Wolf Valley"), the former home of François-René de Chateaubriand in Châtenay-Malabry, 11 km (6.8 mi) south of central Paris.