| FIR | Final Inspection Report | 终期视察报告 |
| FIR | finite impulse response | 有限推进响应 |
| FIR | Far Infrared | 远红外线 |
| FIR | Fast Infrared | 高速红外线 |
| FIR | Frequency Induced Resonance | 频率感应共振 |
| FIR | Fault Isolation Resolution | 故障隔离解决方案 |
| FIR | Field Incident Rate | 现场事故率 |
| FIR | Forschungsinstitut fÜr Rationalisierung (German Institute for Operations Management) | Forschungsinstitut fÜr Rationalisierung (German Institute for Operations Management) |
| FIR | First Information Report | 首次信息报告 |
| FIR | Facility Inspection Report | 设施检查报告 |
| FIR | Firefly Books | 萤火虫书籍 |
| FIR | Full Indicator Reading | 满指示器读数 |
| FIR | Flight Information Region (aircraft) | 飞行信息区（飞机） |
| FIR | Federal Industry and Research (type of grant) | 联邦工业和研究（赠款类型） |
| FIR | For Immediate Release | 立即发布 |
| FIR | Flight Incident Recorder | 飞行事件记录器 |
| FIR | First Impression Report | 第一印象报告 |
| FIR | First Investigation Report | 第一次调查报告 |
| FIR | Financial Inventory Report | 财务库存报告 |
| FIR | Final Inspection Record | 最终检验记录 |
| FIR | Far Infra Red | 远红外 |
| FIR | Flats Industrial Railroad Company | Flats工业铁路公司 |
| FIR | Flight Information Region | 航班信息区域 |
| FIR | File Intermediate Representation | 文件中间表示 |
| FIR | Field Investigation Research | 现场调查研究 |
| FIR | Fact Information Report | 事实信息报告 |
| FIR | Feline Interaction Robot | 猫互动机器人 |
| FIR | Flexible Initiatives Resourcing | 灵活的计划资源 |
| FIR | Fahrner Image Replacement | Fahrner图像替换 |
| FIR | Foundation for the Investigation of Reality | 现实调查基金会 |
| FIR | Force Information Room | 部队信息室 |
| FIR | Field Intelligence Report | 现场情报报告 |
| FIR | Field Investigation Report | 现场调查报告 |
| FIR | Fahrner Image Replacement (CSS method for replacing text with an image) | Fahrner图像替换（用图像替换文本的CSS方法） |
| FIR | Far Infrasound | 远次声 |
| FIR | Found Iron Rod | 找到铁棒 |
| FIR | Future Issue Requirement | 未来问题要求 |
| FIR | Flying Insects and Robots | 飞虫与机器人 |
| FIR | Functional Item Repair/Replacement | 功能性修补/更换 |
| FIR | Full Inspection Report | 完整检验报告 |
| FIR | Fluids Integrated Rack | 流体集成机架 |
| FIR | Flight Information Report | 航班信息报告 |
| FIR | Finite-duration Impulse Response | 有限持续时间脉冲响应 |
| FIR | Fully Indexed Rate | 完全指数化利率 |
| FIR | Failure Insensitive Routing | 故障不敏感路由 |
| FIR | food-irradiation reactor | 食品辐照反应器 |
| FIR | Flow Induced Resonance (underwater acoustics) | 流致共振（水下声学） |
| FIR | fold increase in resistance | 阻力增加倍数 |
| FIR | finite impulse response filter | 有限脉冲响应滤波器 |
| FIR | force-interval relationship | 力间隔关系 |
| FIR | Fairyland In Reality | 现实中的梦幻仙境 |