was born Jean-Louis Charles Garnier on 6 November 1825 in Paris, on the Rue Mouffetard, in the present-day 5th arrondissement. His father was originally from Sarthe, and had worked as a blacksmith, wheelwright, and coachbuilder before settling down in Paris to work in a horse-drawn carriage rental business. He married Felicia Colle, daughter of a captain in the French Army.
Later in life, Garnier would all but ignore the fact that he was born of humble origins, preferring to claim Sarthe as his birthplace.