CTA
- CTA International
- CTAS (disambiguation)
- Cairo Transportation Authority
- California Teachers Association
- California Technology Agency
- Call to Action
- Call to action (marketing)
- Call to action (political)
- Call to arms (disambiguation)
- Canadian Transportation Agency
- Canadian Trucking Alliance
- Cased telescoped ammunition
- Catania-Fontanarossa Airport
- Cellulose triacetate
- Central African Republic
- Central African Republic national football team
- Central Texas Airport
- Central Tibetan Administration
- Central Toronto Academy
- Central de los Trabajadores Argentinos
- Central technical area
- Chain transfer agent
- Charge transfer amplifier
- Chartered Institute of Taxation
- Cherenkov Telescope Array
- Chicago (band)
- Chicago Transit Authority
- Chicago Transit Authority (disambiguation)
- Children's Television Act
- China Tourism Academy
- Chinese Taoist Association
- Chisholm Trail Academy
- Citayam railway station
- Colorado Translators Association
- Columbus Torah Academy
- Commodity trading advisor
- Common Tasks for Assessment
- Common Travel Area
- Common Turkic Alphabet
- Computed tomography angiography
- Conditioned taste aversion
- Consolidated Tape Association
- Constant temperature anemometry
- Consumer Technology Association
- Container Terminal Altenwerder
- Control area (aviation)
- Copyright transfer agreement
- Corporate Transparency Act
- Counter-Terrorism Act 2008
- Craig Tribal Association
- Criminal Tribes Act
- Cryptologic technician
- Crystal Thai Airlines
- Cyprus Turkish Airlines
- Department of Aerospace Science and Technology
- Leucine
- National Defense Authorization Act for Fiscal Year 2021
- Tax Institute (Australia)
- Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA)