As speculation mounted that the singer will be given a state funeral, the RATP transport authority paid its own homage by temporarily changing the name of the Duroc station near Invalides where Napoleon is buried to "DuRock Johnny".
Known as the "French Elvis", Hallyday, 74, lost his long battle with lung cancer on Wednesday.
Adored by young and old, hard-living Hallyday was almost a national monument, selling more than 110 million records despite being almost unknown outside the French-speaking world.
Television channels cleared their schedules to broadcast tribute shows to the star who first came to fame in late 1950s yet managed to cleverly adapt to changing musical styles.
President Emmanuel Macron led the mourning by declaring that "there is something of Johnny in all of us", and his officials said he and his wife Brigitte would attend the funeral.
Speculation is rife that Hallyday, who survived a tough childhood after being abandoned by his alcoholic father, will be given a full state funeral, complete with a procession down the Champs Elysees, the grand ceremonial avenue of the French capital -- an honour usually reserved for France's greatest heroes.ParisrenamesMetrostationafterFrenchrocklegendJohnnyHallyday