Here's the list of Paris museum that are free (always or on certain dates): https://www.parisinfo.com/decouvrir-paris/guides-thematiques/paris-gratuit/musees-et

Here's the list of Paris museum that are free (always or on certain dates): https://www.parisinfo.com/decouvrir-paris/guides-thematiques/paris-gratuit/musees-et-monuments-gratuits-a-paris/les-musees-et-monuments-gratuits-a-paris https://www.parisinfo.com/decouvrir-paris/guides-thematiques... (in EN: https://www.familinparis.fr/en/musee-gratuit-a-paris/ https://www.familinparis.fr/en/musee-gratuit-a-paris/) All those owned by Paris city are free to all, always: https://www.parismusees.paris.fr/en https://www.parismusees.paris.fr/en