Charles Constance César Joseph Matthieu d'Agoult de Bonneval (1747/1749, Grenoble – 1824, Paris), also known as Charles-César-Louis Loup Constance Joseph Mathieu d’Agoult de Bonneval, was a French Roman Catholic bishop, and after his resignation of his diocese a political writer.
Another brother, Antoine-Jean, Vicomte d'Agoult, held the rank of Mestre-de-camp, and was a Commander in the Order of Saint Lazare.
He was named Bishop of Pamiers by King Louis XVI of France on 28 January 1787, and received approval from Pope Pius VI on 23 April 1787.
[3] During the French Revolution he helped prepare the abortive escape train for Louis XVI at Vincennes, but then emigrated, and settled in Coblentz in the faction of the Comte d'Artois.
[4] But he returned to France in 1801, having resigned his bishopric as required by Pope Pius VII, though only after some attempt at negotiating better terms.