Hôtel de Mongelas, Private mansion in Paris, France.

Hôtel de Mongelas is a private mansion in Paris organized across multiple floors around a central courtyard. Its layout includes formal reception rooms, private chambers, and living spaces typical of aristocratic residences from its period.

Antoine Foucquet bought the plot at today's 62 rue des Archives in 1606, and a first mansion was begun there in 1639. In 1703 it passed to Romain Dru, sieur de Montgelas, who had it rebuilt from 1705 to 1707 by master mason Nicolas Liévain, keeping the brick-and-stone garden facade. In 1800 it was bought by Nicolas François Bellart, later procureur général, who had a new staircase built in the right wing between 1813 and 1820.

The mansion's name comes from Romain Dru, sieur de Montgelas, who bought it in 1703 and never lived there. Since 2007 it has housed the extension of the Musée de la Chasse et de la Nature, entered from the neighbouring hôtel de Guénégaud; the two mansions are connected. A Louis XIV portal topped by a maskaron opens onto the rue des Archives.

The mansion stands at 62 rue des Archives in the 3rd arrondissement, in the Marais. It is not a private residence: since February 2007 it has housed the extension of the Musée de la Chasse et de la Nature, whose main rooms are in the adjoining hôtel de Guénégaud, and the two buildings are connected. The museum is open to the public; the brick-and-stone garden facade can be seen from the ruelle Sourdis.

The garden facade of brick and stone survives from the first mansion begun in 1639, and its brick quoins were coated with render during the 1705-1707 works to match the rebuilt courtyard front. The Louis XIV portal on the street ends in a carved mask, and an arched portico remains in the courtyard by the left wing.