Beauvais Airport is around one hour north of Paris. This airport is used mainly for charter flights as well as low cost airlines, although you’re most likely to use this airport if you take one of the cheap Ryanair or Wizzair flights.
An express coach link service departs from outside the terminal building to Paris – Porte Maillot. The coach departs approximately 20 minutes after each Ryanair flight arrival. On return, the coach departs from Porte Maillot (at the Parking Pershing parking garage) 3 hours 15 minutes prior to a Ryanair flight departure. Tickets cost €17 (€15.90 if you book online).
You can also get to Beauvais Airport by taking the train from Paris-Gare du Nord to Beauvais and then getting a connecting shuttle bus to the airport. This option costs €15.40. It is a nicer way to travel into Paris; but takes longer, mainly because the time spent transferring between the train and shuttle bus at Beauvais.