| OA | Office Automatization | 办公自动化 |
| OA | Office Address | 办公地址 |
| OA | Old Age | 老年 |
| OA | open account | 赊帐、往来帐 |
| OA | Operations Analysis | 操作分析 |
| OA | Open Architecture | 开放架构 |
| OA | Obligation Authority | （负担）债务的权限 |
| OA | Official Assignee | 法定受让人 |
| OA | Old Account | 旧帐（户） |
| OA | Omni Antenna | 全向天线 |
| OA | on Alert | 戒备 |
| OA | One Adder | 加1加法器 |
| OA | Out of Action | 停止射击，停止照射；发生故障 |
| OA | Output Axis | 输出轴 |
| OA | Order of the Arrow (National Honor Society of the Boy Scouts of America) | 箭骑士团（美国童子军国家荣誉协会） |
| OA | Operating Agency | 运营机构 |
| OA | Occupational Asthma | 职业性哮喘 |
| OA | Operating Authorization | 操作授权 |
| OA | Operational Area | 操作区域 |
| OA | Ordinary Annuity | 普通年金 |
| OA | Optoacoustics | 光学声学 |
| OA | Offensive Action | 进攻性行动 |
| OA | Optic Axis | 光轴 |
| OA | Orientation Advisor (school) | 迎新顾问（学校） |
| OA | Optical Augmentation | 光学增强 |
| OA | Original Article | 原始文章 |
| OA | Off-line Analysis | 离线分析 |
| OA | Overactive | 过度活跃 |
| OA | Operator Assistant | 操作员助理 |
| OA | Obligational Authority | 义务权限 |
| OA | Obstacle Avoidance | 障碍物回避 |
| OA | Operational Assistance | 运营协助 |
| OA | Office of Applications | 应用程序办公室 |
| OA | On Air (TV, radio) | 广播（电视、广播） |
| OA | Output Acknowledge | 输出确认 |
| OA | Orienteering Australia (Australian Capital Territory) | 定向澳大利亚（澳大利亚首都领地） |
| OA | Occiput Anterior (fetal position) | 枕前（胎儿位置） |
| OA | Offered Again | 再次提供 |
| OA | Operations Aerographer | 操作航空摄影师 |
| OA | Orthogonal Acceleration (mass spectrometry) | 正交加速（质谱） |
| OA | Orchestra Atlanta (Atlanta, GA) | 亚特兰大管弦乐团（佐治亚州亚特兰大） |
| OA | Origin Agent (transportation industry) | 原产地代理（运输业） |
| OA | Online Alumni | 在线校友 |
| OA | Office of Audits | 审计办公室 |
| OA | Osmotic Adjustment | 渗透调节 |
| OA | Order of Avalon (gaming) | Avalon订单（游戏） |
| OA | Organizational Assessment | 组织评估 |
| OA | Old Assyrian | 古亚述人 |
| OA | Orange Anime (Florida japanese culture and media club) | 橙色动漫（佛罗里达日本文化和媒体俱乐部） |
| OA | Orbit Area | 动态观察区域 |
| OA | Ordered Aggregate (Differentiated Services Protocol) | 有序聚合（区分服务协议） |
| OA | Operational Assist/Assembly | 操作协助/装配 |
| OA | Orbiter Ancillary | 轨道器辅助 |
| OA | Order Administration | 订单管理 |
| OA | Online Academy | 在线学院 |
| OA | Orbital Analyst | 轨道分析员 |
| OA | Organization and Administration | 组织和管理 |
| OA | Oral Administration (medicine and educational testing) | 口服给药（医学和教育测试） |
| OA | Oversight & Performance Assurance | 监督和性能的保证 |
| OA | Office of AIDS (California) | 艾滋病办公室（加利福尼亚州） |
| OA | Operations Agreement (NASA) | 运营协议（NASA） |
| OA | ocular albinism | 眼白化病 |
| OA | ovalbumin | 卵清蛋白 |
| OA | Objective Area | 目标区域 |
| OA | Outside Assistance | 外部援助 |
| OA | Office of Administration | 行政办公室 |
| OA | Operational Availability | 运营可用性 |
| OA | Open Access | 开放式访问 |
| OA | Olympic Airways | 奥林匹克航空 |
| OA | Orthogonal Array | 正交阵列 |
| OA | oxalic acid | 草酸 |
| OA | oral airway | 口腔气道 |
| OA | Overeaters Anonymous | 匿名戒馋会 |
| OA | Order of Australia | 澳大利亚令 |
| OA | Outside Air | 外部空气 |
| OA | Overton Arm | Overton手臂 |
| OA | Opera America | 美国歌剧院 |
| OA | Ovarian Atresia | 卵巢闭锁 |
| OA | Oriental Adventures (gaming) | 东方冒险（游戏） |
| OA | Operability Analysis | 可操作性分析 |
| OA | Operational Assessment | 作战评估 |
| OA | Operating Agent | 操作代理 |
| OA | Odessa American (Odessa, TX, USA) | 美国敖德萨（美国德克萨斯州敖德萨） |
| OA | Old Aspen | 旧Aspen |
| OA | Orbital/Orbiter Assembly | 轨道/卫星装配 |
| OA | Open Agility (AKC title) | 开放敏捷性（AKC标题） |
| OA | Old Athen | 老雅典人 |
| OA | Overhead Approach | 架空引道 |
| OA | Operational Architecture | 作战体系结构 |
| OA | Operations Analyst | 运营分析师 |
| OA | Ordering Activity | 订购活动 |
| OA | Office Automation | 办公室自动化 |
| OA | Over Aged | 超龄 |
| OA | Osteoarthritis | 骨关节炎 |
| OA | Office Action | Office操作 |
| OA | Optical Amplifier | 光学放大器 |