Options for transport to Rue Cler

I have stayed on Rue Cler several times and love it, be sure to eat at Cafe Du Marche. I usually just take the train/subway from CGD airport to St. Micheal Station (close to Notre Dame) than switch over to the line that goes to the Invalides (Napoleon's tomb) and there are two different stops that will get you within 2 blocks of Rue Cler. The area is safe and pleasantly historic Paris in nature. I find this is fast and much cheaper than a Taxi (50+ euros vs 10 euros). If you google a metro map of Paris you can follow your route this way:
1) Take the Blue metro from CDG to St. Michel station
2) Take the Yellow Metro to Invalides
3) Take the Lavender line to either La Tour Marbourg or Ecole Miltarie, both of these stations are within 2 blocks of Rue Cler!

Have fun!!

To elaborate on the previous answer:

1) Take the Blue metro from CDG to St. Michel station
2) Take the Yellow Metro to Invalides
3) Take the Lavender line to either La Tour Marbourg or Ecole Miltarie, both of these stations are within 2 blocks of Rue Cler!

The RER and Métro are two different but linked systems, and the RER outside the central part of Paris requires additional ticketing. Métro and RER lines are referred to by their number and destination (Métro) or letter and number and destination (RER). The colours are as described but most people will use the numbers and letters and destinations as above.

1) Take the Blue metro from CDG to St. Michel-Notre-Dame station

That is the RER B train - both routes, B-Robinson and B-Saint-Rémy les-Chevreuse will call at St-Michel-Notre-Dame station.

2) Take the Yellow Metro to Invalides

That thick yellow line is also a RER train, RER C. You want direction Pontoise or Direction Versailles-Chateau or Direction Saint-Quentin-en-Yvelines, and will go 2 stops to Invalides.

3) Take the Lavender line to either La Tour Marbourg or Ecole Miltarie, both of these stations are within 2 blocks of Rue Cler!

That's Métro line 8 Direction Balard, one or two stops.

Enjoy your visit.

Have you been to Paris before? The directions for the metro from CDG are good, and certainly cheaper than a taxi, but beware that most metro stations do not have escalators and you will likely have to carry your bags up and down stairs. You will certainly have to if you arrive at Ecole Militare... perhaps you will not be up to it after a long trans-atlantic flight?
Lately I have been taking the Air France Bus (les cars) from the airport to one of their drop-off points in the city.
Go to the CDG website and then to the ground transportation link for info on this bus. Very comfortable trip into town.
From the drop off point, I then take a short taxi ride to my final destination.

Or you could just do all taxi - sometimes you have to pay to make things easy on yourself.
Perhaps doing the metro/RER could work better going back to CDG?
Just my thoughts...
PS
One of the most important things you need is a map of the metro. there is one in the Rick Steves, and all other Paris guidebooks.
Iphone has an app called Paris Metro that is very good. There are others.

BG makes a good point, and the subject has come up here before. We're also going to the Rue Cler area next year, and from this and other sites, I've determined that the St Michel Notre Dame RER stop has (a) escalators to the surface, and (b) a taxi stand. So my intent is to take RER from CDG to St Michel, and then catch a taxi from there. I do wonder, though, whether Invalides also has escalators to the surface, as it's a fairly major stop. If so, it might be cheaper to transfer to RER C to get to Invalides, and then either taxi or walk the rest of the way. But I've been unable to determine whether Invalides has escalators or elevators. Anybody here know?

-Bob

Having taken both approaches, when I arrive from a transAtlantic flight, I typically take airport transit into the city (for example, the bus) and then spring for a taxi from the drop-off point to my hotel. That's been a reasonable compromise for me, and it means I'm not wandering around the city trying to find my hotel while I'm dragging my luggage.

Thanks for the help and suggestions. I'll probably to the bus into Paris and a taxi from there as the best compromise. I have the Metro app on my phone now and the directions above are clear.

All the advice given above is valid.....its easy on the RER and the Metro, just don't make the mistake I made first time I did it - be certain that when you transfer from the RER to the Metro you don't accidentally exit the entire system!

And don't think that because a station has an escalator that it goes all the way to the surface or that the sucker even works. I'd swear that a couple have been dead since I was a kid in short britches.