ASDF may refer to:
- asdfmovie, an animated sketch comedy series first distributed on YouTube
- Advanced Scientific Data Format, a form of storing astronomical data
- Air Self-Defense Force, in Japan
- Alabama State Defense Force, a military entity
- Alaska State Defense Force, a military entity
- Another System Definition Facility, a build system for Common Lisp
- ASDF, the sequence of letters from the left end of the home row on some keyboard layouts