SDF may refer to:
Computing
- Scientific Data Format, an implementation of the HDF5 standard
- SDF Public Access Unix System
- Simple Data Format, binary data format
- Signed distance function (or Signed Distance Field), used in computer graphics and other applications
- Software development folder
- Spatial Data File, a geodatabase file format
- SQL Server Compact Edition Database File, extension
- Standard Delay Format, for timing data
- Structure data file, a file format for a chemical table file
- Synchronous Data Flow, a restriction of Kahn process networks
- Syntax Definition Formalism, to describe formal languages
Organizations
- Japan Self-Defense Forces
- Scouts de France
- Serb Democratic Forum, Serbs of Croatia
- State defense force, US
- Sudan Defence Force, 1925–1955
- Syrian Democratic Forces, an alliance in the Syrian Civil War
Political parties
- Sikkim Democratic Front, a political party of India
- Social Democratic Federation (United States), 1936–1956
- Social Democratic Federation, UK, 1884–1911
- Social Democratic Forum, a political party in Hong Kong, 2000
- Social Democratic Front (disambiguation), in Cameroon and Ghana
- Socialist Democratic Federation (Japan), 1978–1994
Science
- Silver diammine fluoride, in dentistry
- Stromal cell-derived factor (disambiguation), SDF1, SDF1a, etc.
- Subwavelength-diameter optical fibre
- Synchronous diaphragmatic flutter or hiccup
Other
- Louisville International Airport, Kentucky, IATA airport code
- SDF Group (SAME Deutz-Fahr), an Italian-based agricultural machine manufacturer
- Simplified directional facility, an aviation instrument approach navigational aid
- Stochastic discount factor, an econometrical concept
- Südtirol Digital Fernsehen, a TV station in South Tyrol
- Super Dimensional Fortress, one of several fictional warships in the Robotech/Macross franchise
- Soquel Demonstration State Forest, on the California Central Coast