Sed (disambiguation)
sed is a Unix utility for processing text.

Sed or SED may also refer to:

Science and technology
 Spectral energy distribution, a means of characterizing astronomical sources (also, spectral energy diagram)
 Stochastic electrodynamics, in quantum mechanics
 Shock electrodialysis, a newer type of electrodialysis
 Sedirea (Sed.), a genus of orchids

Medicine
 Selective eating disorder, former name of avoidant/restrictive food intake disorder
 Serious Emotional Disturbance; see emotional and behavioral disorders 
 Spondyloepiphyseal dysplasia congenita, an inherited genetic bone disorder
 Erythrocyte sedimentation rate (sed rate), a haematology test

Technology, engineering and computing
 Surface-conduction electron-emitter display, a flat panel display technology for televisions and monitors
 DEC SED (text editor), a text editor for the TOPS-10, TOPS-20, and VMS operating systems
 Self-encrypting device, a hardware-based full disk encryption
 Single error detection, see Error detection and correction

Organisations
 Socialist Unity Party of Germany (), the communist party of the former German Democratic Republic (East Germany)
 Swiss Seismological Service ()

Education
 Society for Economic Dynamics, an academic association in economics
 New York State Education Department
 Scottish Education Department

Companies
 SED Systems, a Canadian satellite systems integrator and developer (Space Engineering Division)
 Tata Power SED, Tata Power Strategic Electronics Division

Other uses
 Survey of English Dialects
 Strategic Economic Dialogue
 Sed card, a "portfolio-on-a-card" used by models and actors
 Sed festival, in Ancient Egypt
 Shippers Export Declaration, a form required by the U.S. Census Bureau / Bureau of Industry and Security for international shipments under certain conditions