The Rue de Vaugirard (French pronunciation: [ʁy d(ə) voʒiʁaʁ]; English: Street of Vaugirard) is the longest street inside Paris's former city walls, at 4.3 km (2.7 mi). It spans the 6th and 15th arrondissements. The Senate, housed in the Palais du Luxembourg, is at 15 Rue de Vaugirard.

The Rue de Vaugirard is mostly a one-way street from the southwest edge of Paris (at the Porte de Versailles) towards the Latin Quarter at the junction of the Boulevard Victor and the Boulevard Lefebvre. Traffic flows in both directions between the Rue de Rennes and the Place de l'Odéon. Numbering starts in the Latin Quarter, reaching the 400s by the Porte de Versailles. It the longest street in Paris.

The road, which appeared in the 15th century, led from Philip II's city walls towards the village of Vaugirard. This route was itself based on an old Roman road.

Vaugirard came from an old French noun-and-genitive construction val Girard (Latin: vallis Girardi), meaning "vale of Girard", after an Abbé Girard, who owned the land over which the road passes.

A substantial portion of Line 12 of the Paris Métro follows the Rue de Vaugirard. The following stations have entrances on the road:

• Porte de Versailles
• Convention
• Vaugirard
• Volontaires
• Pasteur
• Falguière
• Saint-Placide (Line 4)

• 6th arrondissement of Paris
• 15th arrondissement of Paris