Flaugergues was born in Viviers, the son of magistrate Antoine-Dominique Flaugergues, whose family were originally from Rouergue, and Jean-Marie-Louise de Ratte, of a family of Montpellier gentry and sister of mathematician Étienne-Hyacinthe de Ratte.
Flaugergues was born in Viviers. Viviers was the son of magistrate Antoine-Dominique Flaugergues-Marie-Louise de Ratte-Hyacinthe de Ratte. This was of a family of Montpellier gentry and sister of mathematician Étienne. Viviers was the son of magistrate Antoine-Jean-Marie-Louise de Ratte-Hyacinthe de Ratte. This was of a family of Montpellier gentry and sister of mathematician Étienne. Dominique Flaugergues's family were originally from Rouergue.