ZEI
| Acronym | Definition |
|---|---|
| ZEI | ZEI, Inc. (not and acronym; formerly Zinder Engineering, Inc.) |
| ZEI | Zenith Enterprises, Inc. (investment advisor; California) |
| ZEI | Zone d'Epuration Individuelle (French: Area of Individual Purification; wastewater treatment; Belgium) |
| ZEI | Zentrum für Europaische Integrationsforschung (German: Center for European Integration Research; est. 1995) |
| ZEI | Zero Error Information |