- 4 Star Hotel
- 7Eleven Consultancy Services
- 9mobile Nigeria
- A 24/7 Online Food Delivery Services Company
- A-Net Products Concept
- A.G Leventis Nigeria Limited
- Abdul Latif Jameel Poverty Action Lab (J-PAL)
- Abodes Lagos
- Absa Group
- Abt Associates
- Abuja Clinics
- Accion International
- ACDI/VOCA
- Achieving Health Nigeria Initiative (AHNi)
- ACI Worldwide
- Acronis International GmbH
- Acumen West Africa
- Ad Dynamo International
- Adeeva Capital Limited
- Adkan Construction Company Limited
- Afconrecruit Limited
- Affilbase
- Affordable Cars Limited
- African Development Bank Group (AfDB)
- African Naturalistas