What are the chances of making a one hour connection at Charles Degaul airport?

Is it one ticket?
Are there later flights they can put you on if you don't make the one planned?
Will they put you up in a hotel with meal vouchers if there are none?
Do you absolutely have to be back in the US that day?

Answer those questions and you'll know.

We will be arriving on an Air France flight from Lisbon and catching one going to US. Like to have feed back on thke
probabilities.

This is one of my least favorite airports. IF your first flight is on time, and IF your flights are all booked on a single ticket, then you may be able to make this connection. If your flights are on separate tickets, then I would not attempt this connection at CDG.

If not a single ticket from the airline, the probability is you will be in Paris longer than an hour

CDG is not our favorite airport either. We were on a single ticket, had 2.5 hrs, spent all that time in a massive line. None of us knew what was going on. Several of us were booked on the connecting flight to Seattle. Fortunately Delta was aware of the delay. They held the plane.

It also depends on whether you need to change terminals. If you are flying on a European intercontinental airline without going through passport control leaving Portugal, you may be changing terminals, and will need to go through passport control as you will be leaving the EU in Paris so, IMO, one hour will not be enough time.

That's cutting it too close for me. I do know a person who has done it, her Air France flight was late arriving from SFO at CDG but the connecting flight was also late, which obviously helped, still it was close.

My experience is three separate times getting from an incoming flight to RER. I'd already been through customs in Iceland (all three times) so I didn't have a line for passport check (you won't either). I had only a small carry on bag, so no waiting for luggage (may be true for you if you're checked through on one ticket). I had no security to worry about after leaving the terminal - just had to get a ticket from a machine at RER. Each time it was right at one hour to get to an RER train.

If you have to mess with luggage or security, or have to move from a domestic terminal to an international terminal, I don't think you can make it. I agree with others that I wouldn't try it unless it were on one ticket, where the airline takes care of your bags and has an incentive to get you to your flight on time.

Not a chance I would be willing to bet on.

Last fall we flew into Detroit to Barcelona and Madrid to Detroit, connecting at DeGaulle both ways. Here's how it went:

Our flight from Detroit arrived at CDG on Thursday, 9/21 and we had a 1 hour 45 minute connection. Our flight was early, so we actually had about 2 hours. Border control was a nightmare and we arrived at the gate about 15 minutes before departure.

Returning was even worse. Our connection was 1 hour 45 minutes again. Long lines at border control again with only 3 windows open. We finally got through at 10:02 and our flight was 10:20, so we ran. We got to the buses to go to terminal M to find another huge line. We had to wait through multiple buses and got off the bus at 10:20. DH ran ahead and I got to the gate as fast as I could behind him. Thankfully we got on the flight, since at departure time Delta had 47 passengers missing and they ended up holding the flight for 25 minutes.

CDG is my least favorite. The couple of 90 or 95 minute connections were tight (5 or 10 minutes to spare) even with on-time arrivals.

http://easycdg.com/passenger-information/connecting-flight-connections-paris-cdg-airport/transit-information/

PLAN YOUR JOURNEY

For a smooth connection between flights, it’s important to give
yourself adequate time between your first flight’s arrival and your
next flight’s departure, in order to allow for security checks and any
necessary terminal changes.

Minimum transfer time recommended by ″easy CDG″ : • 70 minutes intra
terminal 1/2/3 • 90 minutes between terminals 1/2/3

These minimum connection times only apply if you book a
through-ticket and any baggage is checked through to your final
destination.
You should allow extra time if you are not in this case.

I’ve taken the early morning AF flight which lands at terminal 2F and made my connection which left from the same terminal with a 65 minute window. Most of the AF flights to the US leave from terminal 2E which is about a 20 - 30 minute walk. You will not have to go through security. Sit as close to the exit of the LIS-CDG flight as possible to get off the plane quickly. Follow the “correspondences” signs to terminal 2E and the proper Hall - K, L or M.

You will not have to go through security.

That may or may not be true, but what is certainly true is that you'll have to go through passport control, since you'll be leaving the Schengen zone. That will increase the time needed.

All interesting comments but probably pointless until the OP confirms traveling on one PNR (ticket) or two separate PNRs.