| Acronym | Definition |
|---|
| CTT | Correios (Portuguese Postal Service) |
| CTT | Certified Technical Trainer |
| CTT | Currency Transaction Tax (various locations) |
| CTT | Charity Technology Trust |
| CTT | Cholesterol Treatment Trialists' (collaboration) |
| CTT | Common Task Training |
| CTT | Commodity Transaction Tax |
| CTT | Cryptologic Technician (Technical) (USN Rating) |
| CTT | Common Task Test (US Army) |
| CTT | Collaborative Team Teaching |
| CTT | Cartridge Tape Transport |
| CTT | Correios, Telégrafos e Telefones (Posts, Telegraphs, and Telephones; Portuguese mail service) |
| CTT | Commander's Tactical Terminal |
| CTT | Character Translation Table |
| CTT | Continuous Treatment Team |
| CTT | Center-Tap Terminated (logic) |
| CTT | Combined Test Team |
| CTT | Color Trails Test (neuropsychology) |
| CTT | Closed, Transferring, and Transferred (ranges) |
| CTT | Compatibility Test Trailer |
| CTT | Consorzio Toscano Trasporti (Tuscany Transport Consortium, Italy) |
| CTT | Connecticut Transit |
| CTT | Connection Traffic Table (Cisco) |
| CTT | Capability to Transmit |
| CTT | Counter Timer Trigger |
| CTT | Chronic Toxicity Test |
| CTT | Compression Translation Table |
| CTT | Collaborative Tools Testbed |
| CTT | Common Test Training |
| CTT | Concur Tasktrees (notation) |
| CTT | Customer Trouble Ticket |
| CTT | Common Training Task |
| CTT | Counter Terror Teams |
| CTT | Council for Travel and Tourism (UK) |
| CTT | Corporate Transformation Team (NAVSEA) |
| CTT | Crew Transfer Tunnel |
| CTT | Cellular Transport Technology |
| CTT | Canadian Transportation Tribunal |
| CTT | Cross Tabulated Table(s) |
| CTT | Cascaded Triplet Topology |
| CTT | Converged Technology Training (Cisco) |
| CTT | Cyber-Toothed Tigers (FFFBI) |
| CTT | Correios, Telefones e Telégrafos (Portugese: Post offices, Telegraphs and Telephones) |
| CTT | Crosby Township Trustees |
| CTT | Computerized Transmission Tomography (clinical scanning method) |
| CTT | Combat Theater Trainer |
| CTT | Communications Tactical Terminal |
| CTT | Contractor Technical Test |
| CTT | Console Tape Transport |
| CTT | Currency Transaction Trust |
| CTT | Combat Training Tank |
| CTT | Chest Thoracostomy Tube |