ORY and CDG are separate airport complexes. An airport change means leaving the arrival process, traveling across the Paris region and entering the departure process again.
Public-transport building blocks
Orly is connected by Metro 14 and Orlyval/RER B; CDG is connected by RER B. The dedicated Paris Region <> Airports ticket is valid for airport journeys on metro/RER/train/Orlyval under the published rules.
Baggage and entry rules
If the first flight arrives internationally, immigration and bag reclaim can consume a large part of the gap. Separate tickets may require a new check-in and bag drop at the second airport.
Do not use train time as connection time
The headline transport duration excludes walking, waiting, disruptions, terminal movement, security and airline cutoffs. Model all of those as separate blocks.
Use the airport-change calculator
Enter the real scheduled gap and conservative estimates for arrival formalities, bags, cross-city movement, security and the onward airline’s check-in cutoff.
Frequently asked questions
Is ORY to CDG an airside transfer?
No. Treat it as a landside airport change unless an airline explicitly provides a protected transfer service.
Can I use the same airport ticket?
Île-de-France Mobilités publishes a dedicated airport ticket for Orly/CDG journeys across the eligible metro/RER/train network. Check current validity before travel.
Sources and verification
Time-sensitive airport, airline, visa, security and transport details should always be confirmed with the relevant official source before travel.