No one knows for sure when the first Jack-o-lanterns were made. In ancient times the Celts celebrated the feast of Samhain (pronounced: SOW'en) in Ireland and Scotland, and that holiday eventually became known as Halloween. The Celts believed that on that day the spirits of the dead roamed the earth and would visit the homes where they once lived. Costumes and lanterns carved from turnips, potatoes and beets were used to frighten away evil spirits, as they are today. The lanterns eventually became known as Jack-o-lanterns.

When Christianity spread through Britain and Ireland, Samhain gradually became known as All Hallow's Eve or Halloween. A tale began to be told in Ireland of a man named Jack, who almost lost his soul to the Devil but who tricks him instead.

Different versions of the tale exist, but in one version, Jack, a n'er-do-well, gets so drunk one Halloween that the Devil comes to steal his soul. Jack delays by asking the devil if they can have one last drink before descending to hell. The Devil agrees, but Jack then says he doesn't have enough money for the drinks, but if the devil is willing to change himself into a coin, they can pay for the drinks and then the Devil can change back again. The Devil agrees and when he changes into a coin, Jack quickly places the coin into his wallet next to a cross, preventing the Devil from changing back. Jack then strikes another bargain with the irate Devil, telling him he will release him only if he promises not to bother Jack for some time.

Years later, Jack is walking down a country road when the Devil comes to claim his soul. Thinking quickly, Jack tempts the Devil to climb a tree for an apple. When the Devil climbs the tree, Jack carves a cross into the tree, preventing the Devil from getting down. Jack then forces the Devil to promise never take his soul, and the Devil, reluctantly, agrees.

Jack eventually dies and tries to get into heaven, but heaven won't have him because he's spent a lifetime being dishonest, drinking, tricking, and being mean. So Jack goes to hell and tries to enter, but he can't enter there either because he'd made the Devil promise never to take his soul. So the Devil tells Jack he has to leave the way he came, by a dark and treacherous path. Frightened, Jack begs the Devil for a light, and the Devil throws Jack a coal from hell. Jack puts the coal into a half-eaten turnip to make a lantern, and turns to roam his path endlessly with nowhere to rest.

In Ireland and Scotland, on Halloween people would place carved or painted turnip or beet lanterns on their doorstep to warn off evil spirits with the lost soul of Jack. When the Irish emigrated to the Americas, they brought with them their Halloween traditions and began carving pumpkins in place of turnips, potatoes and beets, but they are still known as Jack-O-Lanterns.