Mamoudou Gassama won widespread praise after climbing the outside of the building to save the four-year-old.
Video showed him being cheered on by spectators as pulled himself from balcony to balcony to the fourth floor.
After meeting him at the Elysee Palace, President Emmanuel Macron said he would be made a naturalised citizen.
He personally thanked Mr Gassama, gave him a medal for courage and said he would also be offered a role in the fire service.
The drama unfolded on Saturday evening on a street in the north of the city.
Mr Gassama said he had been walking past when he saw a crowd gathered in front of the building.