BEM has a number of meanings:
- In engineering, BEM stands for Boundary Element Modeling or Boundary Element Method. Related: FEM
- Bemba language (ISO 639 alpha-3, bem)
- Józef Bem (1794 - 1850), Polish general, commander-in-chief of the Hungarian army during 1848 revolution
- In science fiction (particularly in bad, camp, or tongue-in-cheek science fiction), is a "Bug-Eyed Monster "; a stereotypical malevolent creature.
- "Bem" is the title of an episode of Star Trek: The Animated Series. It concerns an alien observer who, quite literally, ends up going to pieces.
- "Bem" is the short form of Brotherhood of Evil Mutants, an organization in the X-Men universe.
