| OLS | Orthogonal Least Square | 正交最小平方 |
| OLS | Ontario Land Surveyor (Ontario, Canada) | 安大略省土地测量师（加拿大安大略省） |
| OLS | Off-Line Settling | 离线沉降 |
| OLS | endogenous opiate-like sub stance | 内源性阿片样亚单位 |
| OLS | opiate-like substances | 鸦片类物质 |
| OLS | Optical Line System | 光线路系统 |
| OLS | On- Line Solution | 在线解决方案 |
| OLS | Outer Letter Sheet (philatelic term) | 外层信纸（集邮术语） |
| OLS | Organizational Leadership Skills | 组织领导技能 |
| OLS | Optical Link System | 光链路系统 |
| OLS | Olsten Corporation | 奥尔斯滕公司 |
| OLS | Operation Lifeline Sudan | 苏丹生命线行动 |
| OLS | Operation Life Saver | 操作救生衣 |
| OLS | Organizational Leadership Supervision | 组织领导监督 |
| OLS | Oosterum Loudspeaker Systems | Oosterum扬声器系统 |
| OLS | Nogales, Arizona | 亚利桑那州诺加莱斯 |
| OLS | Online Learning System | 在线学习系统 |
| OLS | Ordinary Least Squares | 普通最小二乘法 |
| OLS | Operational Linescan System | 操作线路扫描系统 |
| OLS | Operation Liberty Shield | 自由盾行动 |
| OLS | Organizational Leadership and Supervision | 组织领导和监督 |
| OLS | Online System | oN线路系统 |
| OLS | Optical Landing System | 光学着陆系统 |
| OLS | Ottawa Linux Symposium | 渥太华Linux研讨会 |
| OLS | Online Service | 在线服务 |
| OLS | Office of Legislative Services (various governments) | 立法事务办公室（各国政府） |
| OLS | Orbital Launch Services | 轨道发射服务 |
| OLS | Online Library System | 在线图书馆系统 |
| OLS | Overlap Save Algorithm | 重叠保存算法 |
| OLS | One-Leg-Stand (field sobriety test) | 单腿站立（现场清醒测试） |
| OLS | Operational Line Scanner | 操作线扫描仪 |
| OLS | Optical Line Scanner | 光学线路扫描仪 |
| OLS | Outlaw Star (anime series) | 亡命之星（动漫系列） |
| OLS | OL Slaton (Junior High School Lubbock, TX, USA) | OL Slaton（美国德克萨斯州卢博克初中） |
| OLS | On Line Support | 在线支持 |