Althea is a female given name.
Althea may also refer to:
- Althea, shrub althea, shrub althaea and rose of althea, common names for Hibiscus syriacus, an ornamental plant that is South Korea's national flower
- Althea, Missouri, United States, a ghost town
- Althea Racing, Italian-based motorcycle road racing team
- Operation Althea, a European Union military operation in Bosnia and Herzegovina
- "Althea", a Grateful Dead song
- Althea, a fictional pulsar from the science-fiction novel The Hercules Text by Jack McDevitt