Hey.Thomas. Are you looking for a ecole (primary), college (middle school) or a lycee (high school)? Based on this broad division I am giving you some names here which I found off the web. Hope it helps! British School of Paris, College Federico Garcia Lorca, Ecole Internationale bilingue (EIB), Ecole Jeannine Manuel, Lycee International-British Section, Lycee International Montessori. Just wait for some more answers on this thread. May be people will have more info on this.
Foreign International schools are the best advisable option as it gives kids the flexibility to learn in their own language without the hassle of learning a new lingo. The major plus point is they offer the same curriculum as the native country and thus help in the transition. You could take a look at these: International Deutsche Schule Paris, Ecole Jeannine Manuel, International School of Paris at Rue Beethoven, The Bilingual Montessori School of Paris, Cours Fides, Douces Maternelles, and Ecole Alsacienne.
The fees of International schools is very expensive, so be careful with your choices. A local French school with seperate English classes or curriculum could be worthwhile. French is just another language after all and I know a family that moved in here from UK a while ago and 10 months later all in the family were speaking fluent French.
Where are you based in Paris? Are you considering your place of stay as a criteria? Instead of going for an international school you could try some French State schools which have international and European option. There are several advantages of enrolling your kids in a local French school. They get fluent in the language and make some native friends, it will help them in the longer run.