One parent and kid are connecting thru Paris on our way back from European trip to USA. We will already be in EU (this we assume, we don’t have to go thru EU immigration security check?) and our luggage will be checked thru to the destination, so we have just carry on bags (which we will make it small).

Is 5 hours enough to do quick run to Paris and be back to board USA bound flight? Kid is 7 yrs old. If it is doable (albeit very tight), what/where do you recommend we should go (i.e., weather permitting, I guess)? If it matters, this will be on Tuesday morning in April 2020. If advance ticket is recommended (going up on the Eiffel Tower?), we will purchase such ticket now.

Thank you!

Here is what you could do. It doesn't make any sense to me for someone to do this, but it is feasible. Take the RER B train, get off at St Michel, see the outside of Notre Dame, walk down through the flower market towards the Louvre, maybe walk through the Tuileries Garden, cross one of the bridges across the Seine and back to St Michel for the train back to CDG. It will cost you about $100, you will spend most of your time on the train and you will have about 1 hour max for your walk.

It's very borderline and depends somewhat on details such as your airline/terminal, coach versus business class, etc. You would need to pick one thing to see which is close to an RER station, the closer to CDG the better.

If you have a USA passport, be aware that exit passport control lines at CDG for DL and AF can be extremely long. Business class or SkyPriority (SkyTeam ElitePlus status) helps, but I've waited over an hour recently just to leave Europe, not counting the lines for check in and security. I was in business class with top tier status.

I'm trying to think of something better than viewing the remains of Notre Dame, but you wouldn't have the time to do any other walking even in the immediate area.

Where in the EU do you arrive from? If it’s a non schengen country then you have to clear French immigration.

also are you sure you have 5 hours? So many people calculate it from landing to departure time and ignore deadlines such as passing through security and gate closing times.

Hi all. Thank you very much for all the helpful pointers. We are arriving from one of the Schengen country, so hoping to skip that French immigration (do we need to go thru any security? We don’t know it’s 1st time connecting via CDG.)
And, 5 hr includes everything, I mean “landing CDG, taxing to the gate, exit first metal, waiting, board USA bound, and off”. We will be on the Air France all the way. What we don’t know is when we exit from the inter EU flight (?is that how you call it?), how much time should we taken into calculation for the security line to re-enter CDG, if we decide to venture out to anywhere? Sadly, no status to expedite that security line for us. One of us is US passport, the other is foreign passport, if that makes any difference.

Paris sounds like an out of plan, any neighboring town near CDG worth visiting for, say, breakfast?

Chantilly and Senlis are interesting small towns just north of CDG but taxi will be expensive and you don't have enough time. Last time I flew out of CDG the security line and passport control took about one hour. That was midday Saturday in June.