| API | American Petroleum Institute | - | Computer Acronyms(common) |
| API | Active Pharmaceutical Ingredient | - | Computer Acronyms(common) |
| API | Air Pollution Index | - | Computer Acronyms(common) |
| API | Atmosheric Pressure Ionization | - | Computer Acronyms(common) |
| API | Application Program Interface | - | Computer and Internet |
| API | Application Program(ming) Interface | - | Human Genome |
| API | Application Programming Interface | - | Medical |
| API | Application Programming Interface | - | Astronomy |
| API | American Petroleum Institute | - | Business and Finance |
| API | Application Program Interface | - | Business and Finance |
| API | Axial Power Indicator | - | Business and Finance |
| API | Absolute Position Indication | - | Business and Finance |
