SD

SD may refer to:

SD (rapper), is a rapper from Chicago
Sekolah Dasar, an Indonesian junior school
Sindhi language's ISO 639-1 code
Sisters of the Destitute, a Syro-Malabar Catholic women's order
Southern Cross Decoration (SD), a South African military award
Spasmodic dysphonia
Storm Data, a NOAA publication summarizing severe weather events in the United States
Sudan Airways' IATA airline designator
Super deformed
Surface Detector

Organizations

[Sicherheitsdienst] Error: {{Lang}}: text has italic markup (help), the intelligence service of the Nazi SS
[Sinistra Democratica] Error: {{Lang}}: text has italic markup (help) or Democratic Left, an Italian political party
Social Democrats (Slovenia), a left-wing Slovenian political party
[Stronnictwo Demokratyczne] Error: {{Lang}}: text has italic markup (help), Democratic Party, a defunct Polish party
Sweden Democrats, a nationalist party in Sweden
Swiss Democrats or [Schweizer Demokraten] Error: {{Lang}}: text has italic markup (help), a right-wing political party in Switzerland

Standard-definition television
Secure Digital, a flash memory card format
Software Distributor, an HP-UX software package management system
Standard deviation, a mathematical statistical measure
Subdwarf star, a star with luminosity 1.5 to 2 magnitudes lower than that of a main-sequence star of the same spectral type
Super Density disc, an optical disc storage format precursor to the DVD