- 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.)