Paris Métro Line 10 is one of the sixteen currently open métro lines in Paris, France. The line links Boulogne–Pont de Saint-Cloud, in Boulogne-Billancourt, to the Gare d'Austerlitz, traveling under the rather bourgeois neighborhoods of the Rive Gauche — the southern half of Paris — the 16th arrondissement and the neighbouring commune of Boulogne-Billancourt.
The line runs entirely underground and stretches 11.7 kilometres (7.3 mi) across 23 stations. It has the least traffic of the fourteen main metro lines, excluding lines 3bis and 7bis.