The Paris Métro, short for Métropolitain, is a rapid transit system serving the Paris metropolitan area in France. A symbol of the city, it is known for its density within the capital's territorial limits, as well as its uniform architecture and historical entrances influenced by Art Nouveau. The system is 245.6 kilometres (152.6 mi) long, mostly underground, as well as its 321 stations of which 61 allow the riders to transfer between the sixteen lines (with an additional four under construction and one in project), all numbered 1 to 14, with two extra branches, 3bis and 7bis, named such as they are former parts of Lines 3 and 7 respectively. Three of these lines (1, 4 and 14) are fully automated, and the additional four are also planned as such. Lines are identified on maps by an individual number and an associated specific colour, all part of an official palette, with the traveling direction indicated by the terminus, the last stop on each line. All trains travel from one end of the line to the other, serving every station along the way. The Paris Métro is operated by the Régie autonome des transports parisiens (RATP), which also operates part of the RER (commuter standard train) network, most of the Francilian tram lines and many bus routes around and within Paris itself.
It is the second-busiest metro system in Europe, as well as the twelfth-busiest in the world. It carried 1.476 billion passengers in 2024, roughly 4.04 million passengers a day, which makes it the most used public transport system in Paris. It is one of the densest metro systems in the world, with 244 stations within the 105.4 km (41 sq mi) of the City of Paris. Châtelet–Les Halles, with five Métro and three RER commuter rail lines, is one of the world's largest metro stations. The system generally has poor accessibility due to its old age (established 125 years ago) and because most of the current infrastructure was built before accessibility standards emerged, with few stations retrofitted since. On the flip side, all new infrastructure and rolling stock meets current accessiblity standards, including extensions of historic lines.
