Those nice folk at RATP, the Parisian equivalent of TfL, kindly publish an annual list of passenger numbers at every Métro station. It's part of a large online datafile which includes maps, pictograms, precise station locations, air quality figures and Pantone colours. The file in question is called Trafic annuel entrant par station du réseau ferré. Importantly the data is for entrances only, not exits nor interchanges. 2018's figures are due out in the next couple of weeks, so what follows are passenger numbers for 2017. RER stations are counted separately, so their passengers do not appear.
Paris's ten busiest Métro stations (2017) 1) Gare du Nord (51m) 2) Saint-Lazare (47m) 3) Gare de Lyon (37m) 4) Montparnasse-Bienvenue (29m) 5) Gare de l'Est (21m) 6) Republique (18.2m) 7) Bibliotheque (18.1m) 8) Les Halles (16m) 9) La Defense (15.3m) 10) ↑1 Bastille (15.2m)
The top 5 are all Métro stations attached to major rail termini. Gare du Nord, at the head of the list, is Europe's busiest railway station. Montparnasse is the busiest Métro station south of the river. Four of the top 10 are on line 4, and four are on line 5. Republique is a major hub served by five different lines. By contrast Bibliotheque, Les Halles and La Defense are served by only one Métro line. Châtelet was in the top 10 last year, but has been nudged out this year by Bastille. If passenger numbers for Châtelet and Les Halles were combined (they form a Bank-Monument-style duo), it'd be in fifth place.
To compare these figures with the London Underground, which counts entrances and exits, we'd have to double them. That'd make the combined Top 10 as follows...
» Gare du Nord, King's Cross St Pancras, Saint-Lazare, Waterloo, Oxford Circus, Victoria, Gare de Lyon, London Bridge, Liverpool Street, Stratford
I've already blogged about the top three stations in this list. Numbers 3-6 are all on line 7bis, the disconnected branch to the northeast of the city. Another two (2 and 9) are on the nearby, even shorter, line 3bis. Another three (1, 7 and 8) are on the buckled loop of line 10, previously discussed. The only other line which gets a look in is line 12, where Falguiere is very close to Montparnasse. Half of the top 10 are served by trains in one direction only.
To compare these figures with the London Underground, again doubling makes sense (although it's not entirely fair for one-way stations). Whatever, the combined Top 10 would be as follows...
» Église d'Auteuil, Roding Valley, Chigwell, Grange Hill, Pelleport, Pré St-Gervais, Chorleywood, North Ealing, Moor Park, Theydon Bois