- ACSI stands for Association of Christian Schools International
- ACSI stands for American Customer Satisfaction Index
- ACSI stands for Association Canadienne des Sciences de l’Information (French)
- ACSI stands for American Communications Services, Inc. (telecommunications company)
- ACSI stands for Anglo-Chinese School (Independent)
- ACSI stands for Atari Computer System Interface
- ACSI stands for Appalachian Clean Streams Initiative
- ACSI stands for Association of Clinical Scientists in Immunology (United Kingdom)
- ACSI stands for Alcoa Closure Systems International (various locations)
- ACSI stands for Antiguo Colegio de San Ildefonso (museum in Mexico City)
- ACSI stands for Afghanistan Civil Service Institute
- ACSI stands for Advanced Computer System Interface
- ACSI stands for Abstract Communications Service Interface
- ACSI stands for America’s Counter-Smuggling Initiative
- ACSI stands for Airport Certification Safety Inspector (FAA)
- ACSI stands for Alcan Composites, Singen (European aluminum plant)
- ACSI stands for Army Chief of Staff for Intelligence (US DoD)
ACSI