China 
Africa 
- Coal slurry pipeline
- Coal tar
- Coal-fired power stations
- Coal-mining region
- Coalbed methane
- Coalescence
- Coalescer
- Coaling
- Coarctation of the aorta
- Coarea formula
- Coarse bubble diffusers
- Coarse structure
- Coarse-grained
- Coastal engineering
- Coastal erosion
- Coastal flooding
- Coastal management
- Coastal morphodynamics
- Coastal plains
- Coastal reservoirs
- Coastal sediment transport
- Coastline paradox
- Coated fabrics
- Coated paper
- Coating
- Coaxial
- Coaxial cable
- Coaxial rotor
- Cob
- Cobalt
- Cobalt acetate
- Cobalt blue
- Cobalt ferrite
- Cobalt hydroxide
- Cobalt oxalate
- Cobalt oxide
- Cobalt oxide nanoparticles
- Cobalt sulfate
- Cobalt sulfide
- Cobalt(ii) nitrate
- Cobalt-56
- Cobalt-60
- Cobalt-chrome
- Cobalt-mediated radical polymerization
- Cobaltite
- Cobaltocene
- Cobb angle
- Cobb-Douglas
- Cobble
- Cobblestone
- Cobie
- Coble creep
- Cobots
- Cobweb
- Cobweb plots
- Cocamide
- Cocamide DEA
- Cocamidopropyl betaine
- Coccidioides posadasii
- Coccidioidomycosis
- Coccoliths
- Coccus
- Coccyx
- Cochineal
- Cochlea
- Cochlear duct
- Cochlear implant
- Cochlear nerve
- Cochlear nucleus
- Cockpit
- Cocoa butter
- Coconut
- Cocrystal
- Coda
- Code Composer Studio
- Code as data
- Code coverage
- Code for Sustainable Homes
- Code generation
- Code injection
- Code of ethics
- Code point
- Code rate
- Code refactoring
- Code reuse
- Code review
- Code words
- Codebook
- Codec 2
- Codec2
- Codecs
- Coded aperture
- Coding
- Coding gain
- Coding regions
- Codomain
- Codon
- Coefficient
- Coefficient matrix
- Coefficient of determination
- Coefficient of moment
- Coefficient of multiple correlation
- Coefficient of restitution
- Coefficient of variation
- Coeliac disease
- Coelomocytes
- Coenzyme B
- Coenzyme M
- Coenzyme q10
- Coercivity
- Coexistence curve
- Cofactor f430
- Cofactors
- Coffee
- Coffee beans
- Coffee grounds
- Coffee ring effect
- Coffee roasting
- Coffee substitute
- Cofferdams
- Coffinite
- Cofiring
- Cogeneration
- Cogging torque
- Cognitive architectures
- Cognitive computing
- Cognitive development
- Cognitive disabilities
- Cognitive disorders
- Cognitive engineering
- Cognitive ergonomics
- Cognitive impairment
- Cognitive load
- Cognitive maps
- Cognitive modules
- Cognitive networks
- Cognitive radio
- Cognitive robotics
- Cognitive systems engineering
- Cognitive walkthrough
- Cognitive work analysis
- Cohen's kappa
- Coherence
- Coherence bandwidth
- Coherence length
- Coherence time
- Coherency
- Coherent control
- Coherent diffraction imaging
- Coherent risk measure