Hôtel d'Aguesseau, Private mansion in 6th arrondissement, France.

The Hôtel d'Aguesseau is an 18th-century private mansion at 18 rue Séguier in the 6th arrondissement of Paris. Its street portal, door leaves included, and the facade at the back of the courtyard have been inscribed as monuments historiques since 26 September 1926. The white stone doorway is framed by deep horizontal grooves and closed by a dark red double door with carved oval medallions, rosettes and a blue plaque numbered 18.

The site held successive mansions: Eu (1300), Artois (1352), Nevers (1472) and Étoile (1536). The 18th-century building took the name Aguesseau when Henri d'Aguesseau (1636-1716), a state councillor, bought it; his son Henri François d'Aguesseau (1668-1751), procurator general of the Paris Parliament, lived there. Ravaged by fire on 27 June 1714, which destroyed many files and led to major lawsuits, it was rebuilt. Later owners included Félix-Claude Le Peletier de La Houssaye de Signy and the family of Cardinal de La Roche-Aymon.

The building has housed the publisher Actes Sud since 1997. The name comes from Henri d'Aguesseau, a state councillor who bought the property, and from his son Henri François, attorney general at the Parlement de Paris, who lived there. The white stone plaque right of the portal commemorates lawyer Georges Pitard.

The mansion stands at 18 rue Séguier in the 6th arrondissement, a short walk from the Odéon and Saint-Michel metro stations. The monumental portal, with its dark red double door and the blue plaque numbered 18, opens directly onto the street; the white stone plaque recalling Georges Pitard is set to its right. The building is a private mansion, so the courtyard facade is not freely open to visitors.

The white stone plaque to the right of the portal records that Georges Pitard (1897-1941), a communist lawyer, kept his office at this address; he was shot as a hostage by the Nazis. The plaque is easy to miss beside the dark red double door.