Paris Métro

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 km² (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. However, all new infrastructure and rolling stock meets current accessiblity standards, including extensions of historic lines.

The first line opened without ceremony on 19 July 1900, during the World's Fair (Exposition Universelle). The system expanded quickly until World War I and the core was complete by the 1920s. Extensions into the suburbs were started in the 1930s. The network reached saturation after World War II and new trains were built in order to allow higher traffic, but further improvements were limited by the network's design and, in particular, the short distances between stations. In 1998, Line 14 was opened with the intention to relieve RER A. Eastbound extension of Line 11 towards Rosny–Bois-Perrier in 2024, is the network's most recent extension. A large expansion program known as the Grand Paris Express (GPE) is currently under construction with four new orbital Métro lines (named lines 15, 16, 17 and 18) around the Île-de-France region, outside the limits of Paris, in order to alleviate the traffic on the near-exclusively radial historic network. Further plans exist for Line 1 east, Line 7 north, Line 10 east, Line 12 south and a merger of Lines 3bis and 7bis, as well as a new proposed Line 19 in the city's northernmost urbanized suburbs.

Besides the Métro, central Paris and its urban area are served by five RER lines (602 km or 374 mi with 257 stations), fourteen tramway lines (186.6 km or 115.9 mi with 278 stations), nine Transilien suburban trains (1,299 km or 807 mi with 392 stations), in addition to three VAL lines at Charles de Gaulle Airport and Orly Airport. This makes Paris one of the cities in the world best served by public transportation. Despite the network's uniform architecture, several of its stations stand out at the hand of their unique design. The Métro itself has become an icon in popular culture, being frequently featured in cinema and mentioned in music. In 2021, the RATP started offering an umbrella lending service at several Métro and RER stations, highlighting the Métro's own rabbit mascot, which advises children on staying away from the closing doors.