Decazes married in Paris on 1 August 1805 Elisabeth-Fortunée, second daughter of Count Honoré Muraire, and who died in Paris on 24 January 1806 without issue.
Decazes married secondly on 11 August 1818 Wilhelmine-Egidia-Octavie de Beaupoil, comtesse de St-Aulaire-Glücksbierg, who died at Versailles on 8 August 1873.