I lived my whole life in the suburbs of Paris until i graduated and I could not recommend more highly the Lycée International of Saint Germain en Laye. It is consistently top or in the top 3 schools of the country, providing all students with a bilingual education. I was personally in the British section until 2012 when i finished high school. The school has 12 different other sections, including american. The children receive 8h a week of american (or british/Spanish/german/japanese/italian etc…) class on top of the french curriculum. If your children are not bilingual in french, they will be given extra help for the first year they arrive and will be bilingual by the end of the year (110% guaranteed). At the end of their high school, they will receive the OIB (Option International du Baccalauréat) which is an internationally recognized ‘end of school’ degree like the British A levels. A vast majority of the american/british students end up studying in America, Britain, Canada and the Netherlands. Only about 10 to 20% stay in France to do ‘prepa’ in order to enter the ‘grandes écoles’ or medicine. The american section all pass SATS and the British section do IGCSEs. Many of the alumni who graduate from my school have finished up at very prestigious universities, including: Harvard, MIT, Northwestern, Tufts, Cornell, Pratt, Rotterdam, Oxford, Cambridge, Bath, Warwick, Bristol, UCL, Kings, London School of Economics, HEC, ESSEC, Polytéchnique. (these are just examples of where some of my anglophone friends from my year, and I, have gone. There are many many other universities that Alumni have and can successfully enter)
If you’re not sure how long you’re staying in Paris for, the outcome of the Lycée International is not just good prospects for university- students also enjoy an immersion into multicultural life, spending their days at school with people from all over the world.
The American School of Paris would be another good option, but fees will be 5 to 10 times more, and French is only a tiny part of their curriculum (as well as other bilingual schools in Paris that offer American curriculum). I know a few people that have been there, not many come out of it speaking french because it’s only taught as a foreign language: basically an expensive american school in Paris.
On the other hand, the Lycée International has a set-up that guarantees your children are bilingual by the end of their first year at the school (they are put into a class with other new kids from around the world, given a special teacher who focuses on the french language. The next year they will ALL be re-integrated into a class with french speaking bilinguals to follow the national french curriculum)
Plus, it is a beautiful set up just 25 mins on the train to central paris, Saint Germain en Laye is where Louis the XIV was born, and the school is actually based on the Old grounds of the NATO headquarters after WW2 (hence why it became an international school, first called SHAPE in the 50s)
here is a link to the american section website.
the wikipedia page for the Lycée International de Saint Germain en Laye also outlines more or less what i’ve said.
Best of luck,
you won’t be disappointed if you choose this option. Definitely worth a look into.