Davis ni a bi ni Fairview, Kentucky, to a moderately prosperous farmer, the youngest of ten children. O dagba ni Wilkinson County, Mississippi, ati ki o tun gbe ni Louisiana. Arakunrin rẹ agbalagba Joseph Emory Davis ni idaniloju ipinnu ti Davis ọdọ si United States Military Academy. Lẹhin ti o gboye, Jefferson Davis sin ọdun mẹfa bi alakoso kan ninu awọn United States Army. O ja ni Mexican-American Ogun (1846-1848), gẹgẹbi ọgagun ti regiment oluranlowo kan. Ṣaaju ki o to Ogun Ilu Amẹrika, o ṣiṣẹ oko nla kan ni Mississippi, eyiti arakunrin rẹ Joseph fun u, o si ni ọpọlọpọ awọn ẹrú 113.
ọdún 1848