Seiyu, or seiyū, is a term for a Japanese voice actor.
Seiyu may also refer to:
- Seiyu Group, a Japanese group of supermarkets, shopping centers, and department stores.
- Seiyu (retailer), a Japanese company, the official head of the Seiyu Group.
- Rikken Seiyūkai, known simply as Seiyūkai, a Japanese political party during the pre-war Empire of Japan.
- Seiyū Hontō (True Seiyū Party), a Japanese political party during the pre-war Empire of Japan that broke away from the Rikken Seiyūkai.