| MAO | Maximal acid output | 最大酸输出量 |
| MAO | Manaus, Amazonas, Brazil - Eduardo Gomes (Airport Code) | 巴西亚马孙州马瑙斯-爱德华多·戈麦斯（机场代码） |
| MAO | master of the art of obstetrics | 产科艺术硕士 |
| MAO | Million And One | 百万加一 |
| MAO | Manaus, AM, Brazil | 马瑙斯，AM，巴西 |
| MAO | Mailing Address Only | 仅为邮寄地址 |
| MAO | Maximum Allowable Offer (real estate) | 最高允许报价（房地产） |
| MAO | Middelbaar Agrarisch Onderwijs | Middelbaar Agrarisch Onderwijs公司 |
| MAO | Major Attack Option | 大规模攻击方案 |
| MAO | Maneuver Affairs Officer | 机动事务官 |
| MAO | Modified Audit Opinion | 修改后的审计意见 |
| MAO | Motivation Ability Opportunity (consumer behavior) | 激励能力机会（消费者行为） |
| MAO | My Arrogant Opinion | 我的傲慢观点 |
| MAO | Med Andra Ord | Med Andra Ord公司 |
| MAO | Mono Amine Oxidase | 单胺氧化酶 |
| MAO | Methyl Aluminoxane | 甲基铝氧烷 |
| MAO | Miss America Organization | 美国小姐组织 |
| MAO | Managerial Accounting Office | 管理会计办公室 |
| MAO | Multiple Acronym Overload | 多首字母缩略词重载 |
| MAO | Maori | 毛利语 |
| MAO | modified anterior oblique | 改良前斜肌 |
| MAO | medial accessory olive | 内侧副橄榄 |
| MAO | monoamine oxidase | 单胺氧化酶 |