With the onset of the French Revolution, he supported the Civil Constitution of the Clergy; a proffered appointment to a high Catholic Church office failed to induce him to alter his position.

[1] Elected to the National Convention by the Pas-de-Calais département, he associated himself with the moderate Girondists and strongly opposed the death sentence imposed on King Louis XVI.

He remained largely ambivalent towards Napoleon, but supported him against Pope Pius VII and the Papal States, providing him historical arguments in a scholarly treatise Sur la puissance temporelle du Pape (On the Temporal Power of the Papacy) in 1809.

[1] The Encyclopædia Britannica Eleventh Edition writes: In politics Daunou was a Girondist without combativeness; a confirmed republican, who lent himself always to the policy of conciliation, but whose probity remained unchallenged.

His Discours sur l'état des lettres au XIIIe siècle, in the sixteenth volume of the Histoire littéraire de France, is a remarkable contribution to that vast collection, especially as coming from an author so profoundly learned in the ancient classics.

All his works were written in an elegant style; but apart from his share in the editing of the Historiens de la France, they were mostly in the form of separate articles on literary and historical subjects.