| GTT | gestational trophoblastic tumor | 妊娠滋养细胞肿瘤 |
| GTT | Global Title Translation | 全局码 |
| GTT | Global Text and Total Conversation Services | 全球文本和总对话服务 |
| GTT | Glucose Tolerance Test | 葡萄糖耐量试验 |
| GTT | Geiger Tube Telescope | 盖革管望远镜 |
| GTT | Gemeenschappelijke Trefwoorden-Thesaurus | Gemeenschappelijke Trefwoorden同义词库 |
| GTT | GlobalTouch Telecom, Inc. | GlobalTouch电信公司。 |
| GTT | Gavin's Tips and Tricks (video episodes) | 加文的小费和伎俩(录像) |
| GTT | Gone To Texas | 去德克萨斯州 |
| GTT | genetic transformation test | 遗传转化试验 |
| GTT | guttae | 口香糖 |
| GTT | Grand Terrace Toastmasters | 大露台演讲会 |
| GTT | Gruppo Torinese Trasporti | Gruppo Torinese Trasporti公司 |
| GTT | General Agreement on Tariffs and Trades | 关税和贸易总协定 |
| GTT | Government Technical Test | 政府技术测试 |
| GTT | Grand Turing Turbo | 格兰德图灵涡轮 |
| GTT | Guttae (Latin: Drops) | Guttae（拉丁语：Drops） |
| GTT | Government Technical testing | 政府技术测试 |