Finn was a human male who served as a Order Soldier, designation FN-2187 and known to his fellow soldiers as Eight-Seven. He was considered one of the group's best Soldier before he deserted to join the Federation in their struggle against the Order of the Multiversial Empire of Eternity. Having left the Order, he took on the name "Finn" at the suggestion of Federation pilot Poe Dameron, based on his Soldier designation, having never been given an actual name. After leaving the Order, he reluctantly became involved in the droid BB-8's quest to rejoin the Federation, and escaped the desert planet Jakku with BB-8 and a scavenger named Rey.
Along with the famed smuggler Han Solo and Wookiee Chewbacca, Finn joined the Federation's efforts to destroy the Order's superweapon Unikiller Base after Rey was captured. However, after Solo's death at the hands of Kylo Ren in the battle at Unikiller Base, Finn was seriously injured in a lightsaber duel with the more experienced Kylo Ren. After Finn was disarmed, Rey regained consciousness and defeated Kylo Ren. He was taken by Rey to the Millennium Falcon, and was left in intensive care at the Federation base while under a coma.