Hôtel d'Hailly d'Aigremont, Private mansion in Lille, France.

Hôtel d'Hailly d'Aigremont is a two-storey private mansion at 45 rue de Roubaix in Lille, built in 1703 as an entre cour et jardin house. Its light stone facade carries a triangular pediment; three round-arched openings mark the ground floor, with a grilled door between two white-framed windows, and three rectangular windows with iron balconies above. A lantern hangs on each side of the door.

Built in 1703 for Pierre-Louis Jacobs d'Hailly, the mansion was confiscated during the French Revolution and sold to a manufacturer, then to a dyer. It passed to the Sisters of Notre-Dame-du-Cénacle and was partly altered in the 19th century. Abandoned by the community at the separation of Church and State, it was bought by Jules Scrive-Loyer in 1907 and ceded to the Ministry of the Armed Forces in 1946.

The building's name recalls Pierre-Louis Jacobs d'Hailly, who commissioned it in 1703; the alternative spelling d'Ailly d'Aigremont also appears in records. From 1946 it passed to the Ministry of the Armies, and it now serves as the residence of the general commanding the French Army's land forces, so the house is a working military residence rather than a museum.

The residence is located on rue de Roubaix and currently serves as an official residence with restricted public access. Visitors can appreciate the exterior architecture and stonework from the street, though the interior spaces are not open to casual tourism.

The garden runs from rue de Roubaix along rue des Canonniers to boulevard Carnot, and the canal des Vieux Hommes once crossed it. The waterway is now covered, but its line still runs through the grounds. The mansion and its garden were listed as monuments historiques on 7 December 1965.