| III | Insurance Institute of India | 印度保险协会 |
| III | Institute of Infection and Immunity (Canada) | 感染与免疫研究所（加拿大） |
| III | Insurance Information Institute | 保险信息学会 |
| III | Indian Institute of Immunology | 印度免疫学研究所 |
| III | Integrated Imagery and Intelligence | 集成图像和智能 |
| III | Innovative Interfaces Inc. | Innovative Interfaces公司。 |
| III | Interstate Identification Index | 州际鉴定索引 |
| III | Immediate Intensive Intervention | 立即强化干预 |
| III | Incapacitating Illness or Injury | 使失去能力的疾病和受伤 |
| III | Institute for Information Industry | 信息产业研究所 |
| III | Integrated Information Infrastructure | 集成信息基础架构 |
| III | Informis Infinitas Inhumanitas (band) | Informis Infinitas Inhumanitas（乐队） |
| III | Insteel Industries, Inc. | Insteel Industries，Inc.公司。 |
| III | Intelligence Integrity Intensity | 智力完整性强度 |
| III | Roman Number 3 | 罗马数字3 |
| III | Instituto Indigenista Interamericano (Inter-American Indian Institute) | 美洲印第安人研究所 |
| III | Interactive Investor International | 互动投资者国际 |
| III | Triremis (Latin: Triremes, epigraphy) | Triremis（拉丁语：Triremis，金石学） |
| III | 3 (Roman numeral) | 3（罗马数字） |
| III | Regiment (Graphical Representation/Military) | 团(图示/军事) |