Dema or DEMA may refer to:
- Dema, an Iranian word for the Towers of Silence
- Dema, an Arabic name meaning the cloud that brings rain to the crops after a drought.
- Dema, Burkina Faso
- Dema, the mythological ancestor of an extended family among Marind-anim
- Dema or Dyoma (Russian: Дёма), a river in Bashkiria, Russia.