- Centrifugal pumps
- Centring
- Centripetal force
- Centroid
- Centrosymmetry
- Ceramic engineering
- Ceramic matrix composite
- Ceramics
- Cerebellum
- Cerebral cortex
- Cerebral palsy
- Cerebrovascular disease
- Ceres
- Cerium
- Cerium oxide
- Cerium sulfate
- Cermet
- Certified reference materials
- Cerussite
- Chain reactions
- Chain scission
- Chain-growth polymerization
- Chainsaw
- Chalcanthite
- Chalcedony
- Chalcocite
- Chalcogenide glass
- Chalcogenides
- Chalcogens
- Chalcopyrite
- Chalk
- Chamosite
- Chapman-Enskog theory
- Characteristic polynomial
- Characterization
- Charcoal
- Charge carrier density
- Charge carriers
- Charge density
- Charge number
- Charged particles
- Charpy impact test
- Chassis
- Chelation
- Chelation therapy
- Chemical affinity
- Chemical bonds
- Chemical burns
- Chemical composition
- Chemical compounds
- Chemical decomposition
- Chemical element
- Chemical engineer
- Chemical engineering
- Chemical equation
- Chemical equilibrium
- Chemical formula
- Chemical kinetics
- Chemical metallurgy
- Chemical polarity
- Chemical potential
- Chemical reaction
- Chemical shift
- Chemical species
- Chemical stability
- Chemical structure
- Chemical substances
- Chemical symbols
- Chemical synthesis
- Chemically inert
- Chemiresistor
- Chemisorption
- Chemistry
- Chemotherapy
- Chemotroph
- Chert
- Chillers
- Chimneys
- Chipseal
- Chipset
- Chirality
- Chirped pulse amplification
- Chisel
- Chitin
- Chlamydomonas reinhardtii
- Chloralkali process
- Chlorate
- Chloride
- Chloride channels
- Chlorine
- Chlorine dioxide
- Chlorine fluoride
- Chlorite
- Chlorite group
- Chlorodifluoromethane
- Chlorofluorocarbons
- Chloroform
- Chloromethane
- Chlorophyll
- Chlorophyll a
- Chloroplatinic acid
- Cholera
- Choline
- Chord
- Chromate and dichromate
- Chromate conversion coating
- Chromatography
- Chrome plating
- Chromic acid
- Chromite
- Chromium
- Chromium carbide
- Chromium oxide
- Chromophores
- Chronic kidney disease
- Chuck
- Chuquicamata
- Chyme
- Cinnabar
- Circadian clocks
- Circle
- Circuit breakers
- Circuit topology
- Circular polarization
- Circular sector
- Circular symmetry
- Circulatory system
- Circumference
- Cisplatin
- Citizen science
- Citric acid
- Civil aviation
- Civil engineering
- Civil engineers
- Cladding
- Clamp
- Classical electromagnetism
- Classical mechanics
- Clastic rock
- Clathrate compounds
- Claus process
- Clausius-Clapeyron relation
- Clay
- Clay minerals
- Cleavage
- Climate change
- Climate system
- Climbing formwork
- Clinker
- Clock