IEM can refer to:
- Integrated Enterprise Modeling
- In ear monitors
- the Iowa Electronic Markets
- Incredible Expanding Mindfuck (Music)
- I.E.M. (album)
- Information Engineering Methodology
- Institute of Electronic Music and Acoustics (Institut für Elektronische Musik und Akustik)
- Institute of Engineering and Management
- Inborn error of metabolism
- Innovative Emergency Management
- Institute of Engineering in Medicine
- Institute for Experimental Mathematics
- Intel Extreme Masters