Odin (オーディン Ōdin) is a recurring summon in the series. He has appeared in every Final Fantasy game from Final Fantasy III through to Final Fantasy IX, as well as Final Fantasy Tactics. Most commonly, Odin will appear and slice though enemies with his sword, cleaving them in two and inflicting Instant Death. Other games give Odin the ability to damage enemies normally as well.

His basic physical characteristics are that of a demonic-looking knight with horns, a long, curved scimitar as his weapon, and a cape. This progressed to also include a lance-type weapon called Gungnir. He always is seen on his horse, who takes on demonic-type attributes as well, such as red eyes and body armor. Sleipnir, Odin's steed in Norse mythology, has eight legs; in some games in the series, Odin's steed has six legs. In Final Fantasy III, Sleipnir can be encountered as a six-legged enemy, while Odin's steed is a normal horse.

He appears as the personal summon to prince Marco Argeno and sacred protector of Lavatania