Paul Tannery's parents were Delphin Tannery, who was an engineer working for the French railways, and Opportune Perrier. Delphin and Opportune Tannery had three children, the eldest being a daughter while the second oldest was Paul and Jules Tannery was the youngest. Delphin Tannery's job with the railways involved him moving around the country depending on where railways were being constructed.
Paul kultihan ng mga magulang ay Delphin kultihan, ay isang engineer na nagtatrabaho para sa French railways, at tamang-tama Perrier. Delphin at tamang-tama kultihan nagkaroon na ng tatlong mga bata, ang pinakamatanda ay isang anak na babae habang ang pangalawang pinakaluma ay Paul at Jules kultihan ay ang bunso. Delphin kultihan ng trabaho sa railways kasangkot sa kanya ang paglipat ng buong bansa, depende sa kung saan railways ay na itinayo.