The Sacred Twins (双聖器, Sōseiki lit. Twin Holy Weapons) are two legendary weapons unique to each nation in Fire Emblem: The Sacred Stones. They were all used by the legendary Five Heroes in battle against the Demon King.
With the exceptions of Latona and Gleipnir, all the Sacred Twin weapons deal bonus damage to monsters. All can only be used by a character who has S rank in the weapon type, except for Sieglinde and Siegmund, which can only be used by Eirika and Ephraim.
- Grado: Gleipnir, the Dark Tome and Garm, the Black Axe.
- Renais: Siegmund, the Flame Lance and Sieglinde, the Thunder Sword.
- Frelia: Nidhogg, the Serpent Bow and Vidofnir, the Winged Lance.
- Jehanna: Excalibur, the Wind Tome and Audhulma, the Ice Blade.
- Rausten: Ivaldi, the Glorious Light and Latona, the Saint's Staff.
- L'Arachel is the only playable royal who has the potential to wield both of the Sacred Twins of her kingdom, as a Valkyrie, though she is unable to do both at the same time due to weapon ranking mechanics.
- Excalibur is the only Sacred Twin without a logical user among the player's army, as there are no Anima magic users from Jehanna that have ties to the royal family.
- Eirika and Ephraim are the princess and prince of Renais, who inherit Sieglinde and Siegmund.
- Innes and Tana are the implied users of Nidhogg and Vidofnir respectively, being the prince and princess of Frelia.
- Duessel and Knoll are the implied users of Garm and Gleipnir due to their ties to Grado's royal family.
- Joshua is the implied wielder of Audhulma as Jehanna's prince.
- L'Arachel as already mentioned is the implied wielder of both Latona and Ivaldi.
- Excalibur is the only Sacred Twin that cannot be wielded by a direct member of the royal family that housed it.
- Fado is the king of Renais, and can wield both Sieglinde and Siegmund, along with Eirika and Ephraim.
- Hayden is the king of Frelia, and can wield Nidhogg along with Innes. Tana is the only one who can wield Vidofnir.
- Vigarde and Lyon are the emperor and prince of Grado, and can wield Garm and Gleipnir, respectively.
- Ismaire is the queen of Jehanna, and can wield Audhulma, along with Joshua.
- Mansel is the Divine Emperor of Rausten, and can wield both Latona and Ivaldi, same as L'Arachel.
- Nidhogg is the only Sacred Twin to make an appearance in Awakening, not counting the game's variation of Excalibur.
- As of yet, Latona is the only Sacred Twin that has not made an appearance in Fire Emblem Heroes.