CTD
- CBS Television Distribution
- CTD (chemotherapy)
- CTD (instrument)
- Carboxy-Terminal Domain
- Carnitine transporter deficiency
- Central de Trabajadores Democráticos
- Church–Turing–Deutsch principle
- Circle the Drain (disambiguation)
- Common Technical Document
- Comparative Toxicogenomics Database
- Connective tissue disease
- Counter Terrorism Department (Pakistan)
- Crash Test Dummies
- Crash to desktop
- Cummins
- Cumulative trauma disorders
- FBI Counterterrorism Division