Musée de la Franc-Maçonnerie, Freemasonry museum in the 9th arrondissement, Paris, France

The Musée de la Franc-Maçonnerie occupies the Hôtel Cadet at 16 rue Cadet, whose street facade is clad in light grey metal panels with four wavy vertical bands and the white lettering "RAND ORIENT DE FRANCE". Inside, a 400 m² permanent room and a 200 m² temporary space follow a looped, clockwise route in two threads: the "fil du temps" for the chronological history and the "fil du maçon" for individual engagement.

A circular of 1 May 1889 ordered the Grand Orient's council to create a "masonic museum" in the Hôtel Cadet, timed for the Revolution's centenary; lodges were asked to send objects and documents to rue Cadet. Under the Occupation the Nazis and Vichy's secret societies service looted the collections, some shown at the anti-masonic exhibition of the Petit Palais (12 October–17 November 1940). The museum reopened in 1973 for the bicentenary, was rebuilt from 1,800 m² of the first two levels and reopened on 11 February 2010.

The museum's name comes from the Grand Orient de France, which founded it in 1889 and still occupies the building at 16, rue Cadet. Its collection includes Voltaire's masonic apron from 1778, Lafayette's masonic sword, a 1723 first edition of James Anderson's Constitutions and satirical prints by William Hogarth. A round plate with a scalloped green rim shows the letter "G", a sun, a moon and a triangle inscribed "JEUVA".

The museum occupies the first two levels of the Grand Orient de France headquarters at 16, rue Cadet, in the 9th arrondissement; the nearest métro stop is Cadet. It is open daily except Sundays and Mondays, and an admission fee is charged. The visit follows a loop through a 400 m² permanent room and a 200 m² temporary exhibition space.

The collection includes a Meissen porcelain figurine from 1740 and satirical prints by William Hogarth. Documents seized by the KGB after World War II were returned from Moscow in 2000, the year the museum received the "musée de France" label.