- ABACUS stands for Association of Building Societies and Credit Unions (Australia)
- ABACUS stands for Armed Forces Billing and Collection Utilization Solution (Military Health System)
- ABACUS stands for Arctic Biosphere Atmosphere Coupling at Multiple Scales
- ABACUS stands for Architecture and Building Aids Computer Unit
- ABACUS stands for Advanced Battlefield Computer Simulation
- ABACUS stands for Automated Budget Analysis/Centralized User System (AFMC system)
- ABACUS stands for Association for British and Chinese University Students (UK)
- ABACUS stands for Association of Bibliographic Agencies of Britain, Australia, Canada and the United States
- ABACUS stands for Austere Backup Communications Unmanned System
- ABACUS stands for Air Battle Analysis Center Utility System
ABACUS