Seina may refer to:
- Seina Ryuenji, an original character for the series, Legend of the Mythic Beasts
- Seina Yuki, a Yu-Gi-Oh! GX character.
- Seina Tsumura, a character for a Digimon Adventurers rewrite
- Seina Yuki, a Beyblade character.
- Seina Clark, a Dragon Booster character.
- Seina Yuki, a Bakugan character, and royal guard of Vestar.
- Seina Yuki, a Yu-Gi-Oh! character set to appear in Memories of the King.