Châtelet–Les Halles station is a major train hub in Paris and one of the largest underground stations in the world. Opened in 1977, it is the central transit hub for the Paris metropolitan area, connecting three of five RER commuter-rail lines and five of sixteen Métro lines. The hub hosts 750,000 travellers per weekday and platforms separated by up to 800 metres (0.5 mi). It is named after the nearby Place du Châtelet public square and Les Halles, the former wholesale food market of Paris, now a shopping mall.

Paris Métro Line 11 is one of the sixteen lines of the Paris Métro. It links Châtelet to Mairie des Lilas in the northeastern suburbs. At a length of 6.3 km and 13 stations served, it is currently the shortest of the 14 main Métro lines but is being extended by 6 stations. With 47.1 million riders in 2017, it is the thirteenth busiest line in the network.