FDE may refer to:
- Fault detection and exclusion, a technique used in global positioning systems
- Federal Directorate of Education, an agency of the Pakistani government
- Fetch-decode-execute cycle, in computer science
- First-degree entailment, a weakening of paraconsistent logic lacking truths
- Førde Airport, Bringeland, in Norway
- Førde Airport, Øyrane, in Norway, closed in 1986
- Forensic document examination, a synonym of "questioned document examination"
- FrameMaker Development Environment, part of Adobe FrameMaker
- Full disk encryption