Petite Ceinture du 15e, Linear urban park in 15th arrondissement, France.

The Petite Ceinture du 15e is a 1.3 km linear park on 3.5 ha of the former Petite Ceinture railway in the 15th arrondissement, running parallel to the boulevards des Maréchaux from place Balard to rue Olivier-de-Serres. The south track is left as it was, rails on wooden sleepers in gravel; the north track is converted into a footpath but kept beneath it. The route sits in a cutting at rue Olivier-de-Serres, then crosses bridges over place Balard, rue Lecourbe, rue Desnouettes, rue du Hameau and rue de Vaugirard.

The southern section of the Petite Ceinture, linking Auteuil to Ivry-sur-Seine, opened in 1867 and served the Citroën factories to the west and the Vaugirard slaughterhouses to the east. Passenger traffic on most of the line ended in 1934, and freight ceased in the early 1990s. In 2011 the city decided to convert this stretch into a green space; work began in 2012 under a light, reversible design demanded by track owner Réseau ferré de France. The first 900 metres, between rue Olivier-de-Serres and rue Desnouettes, opened on 24 August 2013, and the section to place Balard followed at the end of September 2013.

The park's name comes from the Petite Ceinture ring railway that once circled Paris. The southern track is left as it was, able to carry an occasional train, while the northern track became the footpath but is kept beneath it. Educational panels along the route present the local flora and fauna.

The walk runs from place Balard to rue Olivier-de-Serres, with six accesses: place Balard, place Robert-Guillemard, 82 rue Desnouettes, 43 rue Desnouettes, rue de Vaugirard and rue Olivier-de-Serres. Stairs and lifts serve place Balard, 82 rue Desnouettes and rue Olivier-de-Serres. The path sits in a cutting at the Olivier-de-Serres end and crosses bridges over rue Lecourbe, rue Desnouettes, rue du Hameau and rue de Vaugirard. It stops before the tunnel; a footpath between rues Olivier-de-Serres and de Dantzig links it to parc Georges-Brassens.

The southern track was left untouched and can still carry an occasional train, while the northern one became the footpath but survives beneath it. The owner of the rails, Réseau ferré de France, required that the 2012 works stay light and reversible, so the wild vegetation was kept. In May and June 2016 SNCF laid fibre-optic cable between Pont du Garigliano and Montparnasse along this corridor.