Henri Le Floch was born on 6 June 1862 in Caouet in the commune of Plonévez-Porzay, now in Kerlaz, in Brittany. He said he modeled himself on relatives who had remained faithful priests during the French Revolution.
Henri Le Floch's origins and upbringing were influenced by family members who maintained their religious commitment during the tumultuous period of the French Revolution.