DF or df may stand for:
In geography and politics:
- Distrito Federal (disambiguation) or Federal District in two countries:
- Federal District (Brazil)
- Federal District (Mexico)
- Danish People's Party (Dansk Folkeparti)
In computers:
- df, a Unix command to report disk space usage by filesystem
- Direction flag, a flag stored in the FLAGS register on all x86 compatible CPUs
- Dwarf Fortress, a sandbox-style computer game with world simulation and city-building elements, at current state focusing on dwarven civilization
- DeFRaG, a computer game modification
- DragonFable, a game by Artix Entertainment
In science and technology:
- Density function, a mathematical function which has a wide range of applications such as in the study of macromolecular structure
- Methylphosphonyl difluoride, a chemical weapons precursor listed in schedule 1 of the Chemical Weapons Convention
- Direction finding, a technique used to locate radio transmitters
- Decapacitation factor
In other uses:
- Defender (association football)
- Disney Friends, video game
- Degrees of freedom (disambiguation), various measures
- Delta Force
- Dead Frontier, a free browser-based top down third person 3D survival horror MMORPG set in an open world
- DragonForce, an English power metal band