| Acronym | Definition |
|---|
| DEI | Dale Earnhardt, Inc. (racing team) |
| DEI | Directed Electronics Inc. |
| DEI | Departamento de Engenharia Informática (Portuguese: Department of Computer Science; various universities) |
| DEI | Défense des Enfants International (French) |
| DEI | Diffraction Enhanced Imaging |
| DEI | Dayalbagh Educational Institute (India) |
| DEI | Data Exchange Interface |
| DEI | Dabney Eats It |
| DEI | Device Engineering Inc. |
| DEI | Digestible Energy Intake |
| DEI | Direct Exhaust Injection |
| DEI | Dynamic Effect Intake (Mazda) |
| DEI | Detroit Entrepreneurship Institute, Inc. |
| DEI | Dose Equivalent Iodine |
| DEI | Direction de l'Environnement et de l'Intervention (French: Directorate of Environment and Response; Institut de Radioprotection et de Sûreté Nucléaire) |
| DEI | Dielectric and Electrical Insulation |
| DEI | Dartnell Enterprises, Inc. |
| DEI | Development Engineering Inspection |
| DEI | Diesel Engine Inspection |
| DEI | Data Entry Instructions |
| DEI | Dimosia Epichirisi Ilektrismou (Greek: Public Power Company) |
| DEI | Development Exchange, Incorporated |
| DEI | Data Extraction Interface |
| DEI | Departmento Ecuménico de Investigaciones (Ecumenical Research Department; San Jose, Costa Rica) |
| DEI | Dearmond Enterprises, Inc. |
| DEI | De Armond Enterprises, Inc. |
| DEI | Design Engine Inspection |
| DEI | DoD Enterprise Initiative |
| DEI | Dynamic Electronic Institution |
| DEI | Detection Equivalent Irradiance |
| DEI | Doofenshmirtz Evil, Inc. (Phineas and Ferb; TV show) |
| DEI | Department of Electronics and Information (various locations) |
| DEI | Dutch East India |
| DEI | Drop Eligible Indicator (computer networking) |
| DEI | Divide et Impera (Latin maxim; game) |