- AGSI stands for Association of Garda Sergeants and Inspectors (est. 1978; Dublin, Ireland)
- AGSI stands for Association for Global Strategic Information
- AGSI stands for American General Securities Incorporated (various locations)
- AGSI stands for Advanced Growing Systems, Inc. (Marietta, GA)
- AGSI stands for All Guest Supplies International (Switzerland)
- AGSI stands for Automatic Government Source Inspection
AGSI