TheFork users who ate in Compiègne have said really good things about La Table d'Elisa - Hôtel du Nord, Hostellerie du Royal Lieu and Auberge du Bac. Maybe you should give them a try!
Some of the more popular Traditional restaurants that offer vegetarian options on their menu in Compiègne according to TheFork users include:
La Table d'Elisa - Hôtel du Nord, with a 8.8 rating
Hostellerie du Royal Lieu, with a 8.7 rating
Le Castle, with a 8.5 rating
In those days what better than a traditional restaurant to retrieve the comfort of eating at home.