Vegetarian friendly restaurants in Paris?

Almost every restaurant has vegetarian options. Not always vegan but always vegetarian.

You won't have trouble finding this in most places. We LOVE Le Souffle = you can read reviews and see photos on TripAdvisor, but def make RSVP on their official webpage.

there are SO many vegetarian friendly places and even completely vegetarian. My husband and I are vegan and though I have to plan ahead a bit, we eat very well there. Check out the Happy Cow app. He can certainly get omelettes and salads and pastas etc at many places. That said, here are some places you might like...
Faubourg Daimant is a vegan standout, no matter what your dietary pattern. Very creative and cool.
Vege Saveurs near the Bastille for Chinese (totally vegan and totally delish)
La Cantine de Sam (two locations) for Middle Eastern
L'as du Falafel on Rue des Rosiers
Rue du Cail (and the surrounding streets) near the Gard du Nord - lined with Indian restaurants, I like Petit Veg
Cojean is a fast casual chain that has lots of options
Kitchen on Rue des Gravilliers has great breakfast options (unless he is ok with tartines/croissants everyday!)
VGT bowl on Rue de Beaune for a nice healthy lunch
Rose Bakery on Rue de Martyrs
There is a plethora of Asian and Middle Eastern and Italian places where he will find something! The classic French ice cream is Berthillon on Ile St Louis - they have their own shop (though they wholesale so you'll see it elsewhere).

In my experience, you eat best when you have the fewest limitations on what you will eat.

As mentioned many restaurants in Paris have a vegetarian option. For example, I was at Brasserie Rosie last month and there were at least three first courses and two main courses that were vegetarian. One place that is sort of known for having a menu that is great for mixed (vegetarian and meat eating) is Hebe in the 5th arrondissement. Another place like that is Maceo in the 1st arrondissement. The menu at Persil in the 11th arrondissement is pescatarian with several vegetarian or vegan choices. Petrelle in the 9th usually has vegetarian options and it is very good.

Another vote for Persil in the 11th. Thoughtful, well-prepared food at (what we thought were) great value. We liked it enough to go back twice in the same trip. Worth mentioning is Kubri, very near Persil, which is mostly vegetarian, with some meat options. Another outstanding choice, both in taste and value.

I've been in Paris for a while, and there are some great options for vegetarians and vegans.

There is a new vegetarian restaurant in the fashion district called Conscience, and its excellent (14 rue d'Alexandrie 75002 Paris):
https://g.co/kgs/APRsW1U

Also, try out Kick Cafe on the same street with vegetarian baked goods.

We had no issues in restaurants or cafes in Paris with my veggie daughter. There were always salads and veggie dishes that made her happy.

Have a great time!
Lee