SD

SD may refer to:

Places

*South Dakota, United States postal abbreviation
*Sudan, ISO country code
**Sudan Airways, IATA airline designator
*San Diego, California
*San Diego County, California
*San Diego, Texas

In technology

*SanDisk, US-based multinational corporation which designs and markets flash memory card products
*SafeDisc, a CD/DVD copy protection solution by Macrovision Corporation
*Secure Digital card, flash memory card format used in portable device, including digital cameras and handheld computers
*Self Destruct, in some video games.
*Software Distributor, an HP-UX software package management system
*Standard-definition television
*SharpDevelop, a free and open source IDE for the C# Visual Basic .NET programming languages

In politics

*Sicherheitsdienst, Security Police, the intelligence service of the Nazi SS
*Sinistra Democratica, Italian political party.
*Social Democrats (Slovenia), a left-wing Slovenian political party
*Stronnictwo Demokratyczne, a defunct Polish party
*Swiss Democrats (Schweizer Demokraten) A right-wing - political party in SwitzerlandSilenced, put after a gun name to indicate the presence of a *Silencer*

Government

*School district

In mathematics

*Standard deviation, statistics
*Significant digits, a method of expressing error in measurement
*Systems dynamics modeling

In Medicine

*Spasmodic dysphonia
*Schizoaffective disorder

In Music

*Godin SD, a guitar manufactured by Godin Guitars, a Canadian guitar

Other

*Sales and Distribution, business
*Silver & Deming, a type of reduced-shank drill bit
*Sindhi language
*Suppressed, a suffix placed at the end of a firearm's model name to note it is fitted with a suppressor.
*Sustainable Development, Environmental, economic and social development that meets the needs of the present without compromising the needs of future generations
*Super deformed, an art style in which characters are drawn with short, stubby, highly exaggerated builds
*SmackDown!, an abbreviation for SmackDown! a WWE Friday night show
*Scooby Doo
*SD1 (further disambiguation)