A
- ABVP: Akhil Bharatiya Vidyarthi Parishad
- AC: Alternating Current; Ashoka Chakra
- ACU: Asian Currency Union
- AD: anno Domini; in the year of Lord Christ
- ADB: Asian Development Bank
- ADC: Aide-de-Camp; Access Deficit Charge
- ADF: Asian Development Fund
- ADS: Air Defence Ship
- AJT: Advanced Jet Trainer
- AG: Accountant General; Adjutant General
- AI: Air India
- AIDS: Acquired Immune Deficiency Syndrome
- AIIMS: All India Institute of Medical Sciences
- AIR: All India Radio; Annual Information Report
- AITUC: All India Trade Union Congress
- AJT: Advanced Jet Trainer
- ALH: Advanced Light Helicopter
- AM: ante meridiem; before noon
- AMC: Army Medical Corps; Asset Management Companies
- AME: Associate Member of the Institute of Engineers
- APPLE: Ariane Passenger Payload Experiment
- APEC: Asia-Pacific Economic Cooperation
- APC: Agricultural Prices Commission
- APPU: Asian Pacific Postal Union
- ARC: Asset Reconstruction Company
- ASCII: American Standard Code for Information
- ARDR: Agricultural and Rural Debt Relief
- ASAT: Anti-Satellite weapon
- ASC: Army Service Corps
- ASCI: Advanced Strategic Computing Initiative
- ASEAN: Association of South-East Asian Nations
- ASEM: Asia-Europe Meeting
- ASIMO: Advanced Step in Innovative Mobility
- ASLV: Augmented Satellite Launch Vehicle
- ASMA: Antarctica Specially Managed Area
- ASSOCHAM: Associated Chambers of Commerce and Industry
- ATA: Air Time Authority; Allen Telescope Array
- ATC: Air Traffic Controller
- ATM: Automatic Teller Machine
- ATR: Action Taken Report
- ATV: Automatic Transfer Vehicle
- AUM: Assets Under Management
- AVC: Army Veterinary Corps
- AVM: Additional Volatility Margin
- AWACS: Airborne Warning and Control System
