I'm coming from Portugal to Paris to spend New Year's Eve. I'm staying out of borders of Paris (Mairie d'Ivry station) so I need to know if the Metro works til' late night on the night of 31 December.
Paris Metro on New Year's Eve - Metro Line 7 will run till last train at 02:15, after which the closest station will be Olympiades on Metro Line 14 that will run all night through till normal morning service. Olympiades station on Metro line 14 is about a 30 minute walk from Marie d'Ivry station.
More info on Paris Metro New Year's Eve hours and schedules (updated)