Orlybus is an express bus service linking the Orly airport to the metro/RER station at Place Denfert-Rochereau in Paris. Buses leave every 15-20 minutes from Orly-sud, gate H platform 4 and Orly-west, gate J Level 0 at Orly airport with daily departures from 6am to 11:30pm. In Paris the Orlybus runs every 15-20 minute from Denfert-Rochereau metro/RER station with daily departures from 5:35am to 11pm. The ticket is 5,80 euros and the trip usually takes around 30 minutes. Tickets can be bought on the bus, ticket offices at Place Denfert Rochereau and Orly Sud departure points and from tickets machines at bus stops.

Tel: 01-40-02-32-94
http://www.ratp.info/orienter/aeroport_orlybus.php