| Acronym | Meaning |
| CTT | Capability to Transmit |
| CTT | Career Technical Training (various organizations) |
| CTT | Combat Theater Trainer |
| CTT | Combat Training Tank |
| CTT | Combined Test Team |
| CTT | Commander's Tactical Terminal |
| CTT | Committee on Technology Transfer (various organizations) |
| CTT | Common Task Test (US Army) |
| CTT | Common Task Training |
| CTT | Common Test Training |
| CTT | Common Training Task |
| CTT | Communications Tactical Terminal |
| CTT | Compatibility Test Trailer |
| CTT | Connecticut Transit |
| CTT | Console Tape Transport |
| CTT | Continuous Treatment Team |
| CTT | Contractor Technical Test |
| CTT | Conversion to Type (training; UK) |
| CTT | Corporate Transformation Team (NAVSEA) |
| CTT | Correios, Telégrafos e Telefones (Posts, Telegraphs, and Telephones; Portuguese mail service) |
| CTT | Counter Terror Teams |
| CTT | Crew Transfer Tunnel |
| CTT | Crosby Township Trustees |
| CTT | Cryptologic Technician (Technical) (USN Rating) |
| CTT | Currency Transaction Tax (various locations) |