| Acronym | Meaning |
| CMBR | Completely Mixed Batch Reactor |
| CMC | Ceramic Matrix Composite |
| CMC | Conditional Moment Closure [model] |
| CMC | Coupled Multiconfiguration |
| CMC | Critical Micelle Concentration |
| CMC-SCF | Complete Multiconfiguration Self-consistent Field |
| CMCPE | Chemically Modified Carbon-paste Electrode |
| CMDL | Climate Monitoring And Diagnostics Laboratory (NOAA Boulder |
| CME | Center For Marine Exploration |
| CME | Community Modelling Effort |
| CME | Chemically Modified Electrode |
| CME | Coronal Mass Ejection |
| CME | Crucible Melt Extraction |
| CMF | Clay Minerals File (of Digitized X-ray Diffraction Traces) |
| CMF | Colloid Metal Film |
| CMF | Completely Mixed Flow |
| CMF | Continuous Microfiltration |
| CMF | Crossflow Microfiltration |
| CMI | Cell-mediated Immunity |
| CMI | Corrective Measures Implementation |
| CMIR | Carter Maximum Incremental Reactivity |
| CML | Chronic Myelogenous Leukemia |
| CMLS | Chemical Movement In Layered Soils |
| CMM | Compositionally Modulated Multilayers |
| CMNOS | Complementary Metal Nitride/Oxide Semiconductor |
| CMO | Canonical Molecular Orbital |
| CMO | Complex Molecular Orbital Method |
| CMOD | Crack Mouth Opening Displacement |
| CMOS | Complementary Metal Oxide Semiconductor |
| CMP | Cellular And Molecular Pharmacology |
| CMP | Chemical Measurement Process |
| CMP | Capacitively Coupled Microwave Plasma |
| CMP | Cartilage Matrix Protein |
| CMP | Chemical Mechanical Polishing |
| CMP | Compact Model Potential |
| CMP | Cytidine 5'-monophosphate |
| CMR | Colossal Magnetoresistance |
| CMR-CI | Contracted Multireference Configuration Interaction |
| CMRA | Chemical Migration And Risk Assessment |
| CMS | Compact Muon Solenoid |
| CMS | Carbogenic Molecular Sieves |
| CMS | Complete Model Space (in Many-body Calcns.) |
| CMS | Comprehensive Modeling System |
| CMS | Corrective Measures Study |
| CMSA | Consolidated Metropolitan Statistical Area |
| CMSM | Carbon Molecular Sieve Membrane |
| CMSM | Continuum Multiple-scattering Model |
| CMSSM | Constrained Minimal Supersymmetric Standard Model |
| CMT | Charcot-Marie-tooth Disease |
| CMT | Cadmium Mercury Telluride |