| Acronym | Meaning |
| EOM-CC | Equation Of Motion-coupled Cluster |
| EOPP | Earth Observation Preparatory Program |
| EOR | Enhanced Oil Recovery |
| EORCU | European Ozone Research Coordinating Unit |
| EOS | Earth Observing System |
| EOS | Equation Of State |
| EOSDIS | Earth Observing System Data Information System |
| EOSP | Earth Observing Scanning Polarimeter |
| EOT | Equivalent Oxide Thickness |
| EOTC | European Organization For Testing And Certification |
| EOX | Extractable Organic Halides |
| EP | Electrostatic Precipitator |
| EP | Extraction Procedure |
| EP TOX | Extraction Procedure Toxicity Test (USEPA Method) |
| EPA | Environmental Protection Authority (Australia) |
| EPA | United States Environmental Protection Agency |
| EPA | Electron Population Analysis |
| EPA | Environment Potential Approach (in Electronic-structure Calcn.) |
| EPA | Extended Pair Approxn. (in Elec. Cond. Calcn.) |
| EPAAR | EPA Acquisition Regulation Manual |
| EPACML | Environmental Protection Agency's Composite Landfill Model |
| EPACSAR | EPA Chemical Activities Status Report |
| EPBRE | External Pressure Balanced Ref. Electrode |
| EPC | European Patent Convention |
| EPC | Epoxy Polymer Concrete |
| EPC | Evaporative Pattern Casting |
| EPCE | Effective Pair Correlation Energy Method |
| EPCE | Enhanced Pre-coat Engineering |
| EPCE-F2(SIGM | Effective Pair Correlation Energy Method With The Factor-two (f2) Approximation For Sigma-electron Systems |
| EPCIA | Evolving Principal Component Innovation Analysis |
| EPCRA | Emergency Planning And Community Response Act |
| EPD | Electrophoretic Deposition |
| EPDM | Ethylene-propylene Diene Monomer |
| EPEBS | Enhanced Proton Elastic Backscattering |
| EPEC | Enteropathogenic Escherichia Coli |
| EPEN | Empirical Potential (based On Interaction Of) Electrons (and) Nuclei |
| EPER | European Pollutant Emission Register |
| EPES | Elastic Peak Electron Spectroscopy |
| EPFM | Elasto-plastic Fracture Mechanics |
| EPHMRA | European Pharmaceutical Market Research Association |
| EPI | Echo-planar Imaging |
| EPI | Electronic Patent Index |
| EPIC | Electronics Properties Information Center |
| EPIC | European Prospective Investigation Into Cancer And Nutrition |
| EPIC | Erosion-productivity Impact Calculator |
| EPICA | European Project For Ice Coring In Antarctica |
| EPKR | Electrochem. Polarization Kinetic Reactivation |
| EPLD | Erasable Programmable Logic Device |
| EPM | Electron Probe Microscopy |
| EPM | Empirical Pseudopotential Method |