- ACORN stands for Association of Community Organizations for Reform Now
- ACORN stands for ARC (Australian Research Council) Communications Research Network
- ACORN stands for Accelerated Community Oncology Research Network
- ACORN stands for Alliance to Conserve Old Richmond Neighborhoods (Virginia)
- ACORN stands for Additive Congruential Random Number
- ACORN stands for AIDS Community Resource Network
- ACORN stands for A Classification Of Residential Neighborhoods (CACI International Inc.)
- ACORN stands for Arlington County Online Resource Network (Arlington, VA online library system)
- ACORN stands for Aviation, Construction, Ordnance, Repair, Navy
- ACORN stands for Arms Control Research Network
- ACORN stands for Automated Correspondence Online Response Network
ACORN