- DIAR stands for Defence Industry Aerospace Report (Australia)
- DIAR stands for Defense Intelligence Agency (DIA) Regulation (US DoD)
- DIAR stands for Document Image Analysis and Retrieval (workshop)
- DIAR stands for Department of Interior Acquisition Regulations
- DIAR stands for Dextran-Induced Anaphylactoid Reaction
- DIAR stands for Digital Image Amplification Radiography
DIAR