| Acronym | Definition |
|---|
| TCI | Touring Club Italiano |
| TCI | Turks & Caicos Islands |
| TCI | Texas Correctional Industries |
| TCI | To Come In (hospital appointments) |
| TCI | Tree Climbers International |
| TCI | Temperament and Character Inventory |
| TCI | Telecommunication Company of Iran |
| TCI | Target Controlled Infusion |
| TCI | Teachers' Curriculum Institute |
| TCI | Technical Career Institute |
| TCI | Team Canada Inc |
| TCI | Tokyo Chemical Industry |
| TCI | Tufts Climate Initiative |
| TCI | Tall Clubs International |
| TCI | Tag Control Information |
| TCI | The Catfish Institute |
| TCI | Telephone Collectors International |
| TCI | Total Capital Investment |
| TCI | Theme Centered Interaction (Ruth Cohn communication method) |
| TCI | Trip-Cancellation Insurance |
| TCI | Takeda Chemical Industries, Ltd (Japan) |
| TCI | Transit Capital Improvement |
| TCI | Telecom Cook Islands Ltd |
| TCI | Taycheedah Correctional Institution (Fond du Lac, Wisconsin) |
| TCI | Trustworthy Computing Initiative (Microsoft) |
| TCI | Telecommunications Incorporated |
| TCI | Transportation Clubs International |
| TCI | The Chubb Institute |
| TCI | Tenerife, Canary Islands, Spain - Tenerife Norte Los Rodeos (Airport Code) |
| TCI | Turks & Caicos Airways (ICAO code) |
| TCI | Total Cost Indicators (UK) |
| TCI | Teen Challenge International |
| TCI | Truncated Channel Inversion |
| TCI | Texture Coordinate Index (Microsoft DirectX) |
| TCI | Texas Certified Investigator |
| TCI | Tennessee Coal and Iron Company |
| TCI | Travel Corporation of India, Ltd. |
| TCI | Transistorised Coil Ignition |
| TCI | Time Change Item |
| TCI | Technology Confirmation/Innovation |
| TCI | Tidewater Consultants, Inc. |
| TCI | Terminal Command Identify |
| TCI | Terrain Clearance Indicator |
| TCI | Technology Commercialization Initiative |
| TCI | Transistorized Pointless Ignition |
| TCI | Trajectory Computation Infrastructure |
| TCI | Tire Cost Index |
| TCI | Transaction Content Integration |
| TCI | Teleconsult International |
| TCI | Terminal Communications Interface |
| TCI | TELUS Communications Incorporated (Western Canada phone service) |
| TCI | Toral Cast Integrated Technologies |
| TCI | Training Continuum Integration |
| TCI | Twentieth Century Insurance |
| TCI | Tree Classics, Inc. |