Seiki could refer to:
- Hida Seiki, the defender of the Kaiu Wall.
- Kakita Seiki, the courtier.
- Matsu Seiki, the Guard Commander of Toshi no Naishou.
- Seiki, a retainer of the Usagi family in 1123.
- Yoritomo Seiki, the kolat.
- Yotsu Seiki, the daughter of Yotsu Yatoshin.