| Acronym | Meaning |
| CEBAF | Continuous Electron Beam Accelerator Facility |
| CEC | Commission Of The European Communities |
| CEC | Capillary Electrochromatography |
| CEC | Cation Exchange Capacity |
| CECE | Combined Electrolysis And Chemical Exchange |
| CED | Cohesive Energy Density |
| CEDAR | Coupling, Energetics, And Dynamics Of Atm. Regions [project] |
| CEDE | Committed Effective Dose Equivalent |
| CEDI | Continuous Electrodeionization |
| CEDIA | Cloned-enzyme Donor Immunoassay |
| CEDRA | Controlled Simple Excitation For Dephasing Rotational Amplitudes |
| CEE | Center For Environmental Education |
| CEEC | Capillary Electrophoresis/electrochemistry |
| CEEES | Committee Of European Environmental Engineering Societies |
| CEEL | Community Emergency Exposure Level |
| CEELS | Core Electron Energy Loss Spectroscopy |
| CEEM | Center For Energy And Environmental Management |
| CEES | 2-chloroethyl Ethyl Sulfide |
| CEES | Committee On Earth And Environment Sciences (US) |
| CEF | Chicken Embryo Fibroblast |
| CEF | Crystal Electric Field |
| CEFIC | Associazione Europea Dell'industria Chimica |
| CEFIC | Conseil Europeen Des Federations De L'industrie Chimique |
| CEFIC | European Chemical Industry Association |
| CEGB | Central Electricity Generating Board |
| CEH | Cholesteryl Ester Hydrolase |
| CEI | Committee On Environmental Improvement |
| CEI | Cation Exchange Index |
| CEIA | Capillary Electrophoresis Immunoassay |
| CEIC | Caribbean Environmental Information Center |
| CEIP | Coastal Energy Impact Program |
| CEIS | Center For Environmental Information And Statistics (EPA) |
| CELDS | Computer Aided Environmental Legislative Data System |
| CELFA | Composition Evaluation By Lattice Fringe Analysis |
| CELIA | Competitive Enzyme-Linked Immunoassay |
| CELIAS | Charge, Element And Isotope Analysis System |
| CELISA | Competitive Enzyme-linked Immunoabsorbent Assay |
| CELRF | Canadian Environmental Law Research Foundation |
| CELS | Characteristic Energy Loss Spectroscopy |
| CELSIUS | Cooling With Electrons And Storing Of Ions From The Uppsala Synchrocyclotron |
| CELSS | Controlled Ecological Life Support System |
| CEM | Continuous Emissions Monitoring |
| CEM | Conventional Electron Microscope |
| CEM | Corrected Effective Medium (for Atomic Interactions) |
| CEMAS | Complete Element Matrix Analysis From Scattering |
| CEMC | Canadian Environmental Modelling Centre |
| CEMC | Canonical Ensemble Monte Carlo |
| CEMOS | Complementary Enhanced Metal-oxide Semiconductor |
| CEMS | Conversion Electron Moessbauer Spectroscopy |
| CEMS | Continuous Emissions Monitoring System |