The Palais de la Légion d'honneur (French for "Palace of the Legion of Honour") is a historic building on the Left Bank of the River Seine in Paris, France. It houses the Musée de la Légion d'honneur ("Museum of the Legion of Honour") and is the seat of the Légion d'honneur, the highest French order of merit.
The original Hôtel de Salm was constructed between 1782 and 1787 by the architect Pierre Rousseau (1751-1810) for the German prince Frederick III, Prince of Salm-Kyrburg. The revolutionary government nationalised the building, and from 13 May 1804, it was renamed the "Palais de la Légion d'honneur" and became the seat of the newly created Légion d'honneur. The interior was remodeled for that purpose by Antoine-François Peyre, and new exterior sculptures were added by Jean Guillaume Moitte and Philippe-Laurent Roland.
An additional building was added in 1866 along the then-new rue de Solférino, but the palace was burned in 1871 by the Paris Commune. A replica was rebuilt soon afterwards under Anastase Mortier, with painters Jean-Paul Laurens and Théodore Maillot providing interior decoration. An additional building was added from 1922-1925 on rue de Bellechasse in order to house a museum of the Légion d'honneur.
The Hôtel de Salm was a favorite of Thomas Jefferson, who singled it out as a model for the American public buildings of Washington, DC. He had observed its construction during his stay in Paris in 1784-1789, and his design for Monticello, his own estate, was based on it. The California Palace of the Legion of Honor, a three-quarter scale replica of the Hôtel de Salm, was constructed in San Francisco in 1924; it houses a fine arts museum.
In Haarlem in the Netherlands, the banker Henry Hope had his Villa Welgelegen built to resemble the Hôtel de Salm. In Rochefort-en-Yvelines (near Paris), there is a larger-scale replica of the Hôtel de Salm. It was built between 1899 and 1904 for the wealthy business magnate Jules Porgès by the architect Charles Mewès, and it is known as the Château Porgès de Rochefort-en-Yvelines; today, it is a golf club.