Charles DeGaulle to ORLY Time Frame

See http://www.ricksteves.com/travel-tips/transportation/connecting-in-europes-hub-airports.

Ouch! Good luck, hope you make it, but I'm giving 5 to 1 you don't. RATP says 1 hour 15 minutes "tous rapide" (fastest) Take RER B to Denfert Rochereau and change to the Orlyval shuttle tram.
If your plane lands on time, and you can get through customs and immigration in 1 hour, and you don't have any checked luggage, and you don't get lost on the way, you'll have a chance.
Edit-And you have euro coins in you pocket so you can use the vending machine to buy your ticket so you don't have to wait 1/2 hour in the ticket line. The fare is 20.90 euro per person.

You won't make it by mass transit. Maybe with a taxi.

If this is an Air France itinerary and on one itinerary, An Air France representative will put you on the Air France bus that connects the two airports. Can you make the connection after going through passport, baggage claim and all the rest at that enormous airport, I doubt it.

Bets' reply has the most merit if the two flights are a continuum since all three segments would be in the same semi-organization and would thus contain a warranty of onward transportation.

If that's not the case, the bus only leaves every periodically (thirty minutes ?), so that if you just missed one the taxi could make up the half hour. Road times are going to be the same.

I know where a bus stop is at Roissy T2, but don't know if there are others. I do know that the bus hits both east and west terminals down at Orly. I've never heard of Transvia. The problem, then, has become the number of stops, whereas the taxi would be uninterrupted movement between two distinct points.

Thank you for the great feedback. We are working on rescheduling that flight.