Encyclopedias, Almanacs, Transcripts, and Maps
- Comenius, Johannes Amos
- Cometabolism
- Commercial and Industrial Uses of Water
- Commercial Fishing
- Commission for Environmental Cooperation
- Comparative Mythology
- Comparative Religion
- Comparative Risk
- Competitive Exclusion
- Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
- comprehensive school
- Computer Disposal
- computer network
- Conall Cernach
- Concentricycloidea (Sea Daisies)
- Conchostraca (Clam Shrimps)
- Condensation Nuclei
- Confession of Sins
- Confucianism in Japan
- Confucianism in Korea