The Gotei 13 (護廷十三隊, Goteijūsantai; 13 Division Imperial Guards, 13 Court Guard Squads in the English dub, 13 Court Guard Companies in the English manga) is the primary military branch of Soul Society. It is also the main military organization that most Shinigami join after the academy. 

The History of the Gotei 13 is somewhat unknown. All that is currently known is that it was founded by the current Captain-Commander Genryusai Shigekuni Yamamoto.

The Gotei 13 serves as a military force with its primary responsibilities consisting of:

• The defense of the Seireitei, the center of Soul Society.
• The deployment of Division members into enemy territory for combat operations.
• The deployment of Task Forces as defensive measures in the world of the living. 

The Gotei 13, in contrast to the normal operations of modern-day militaries, does not operate as a cohesive unit normally. The command of the divisions are generally left to the discretion of its particular Captain, who commonly runs it whatever way he or she sees fit, allowing for the change of a division's traditional duties to an entirely new set and even the creation of a separate institution connected to the division. The Gotei 13's main duty is to defend the Seireitei but they are also allocated districts in Rukongai to defend. In addition to these duties, Shinigami also have to deal with the business of being assigned to the Human World.