SD

SD may refer to:

• Salvia divinorum, a psychoactive plant
• Sekolah Dasar, an Indonesian junior school
• Sindhi language's ISO 639-1 code
• Sisters of the Destitute, a Syro-Malabar Catholic women's order
• Sleeping Dogs, a 2012 video game
• Slobodna Dalmacija, a newspaper
• Southern Cross Decoration (SD), a South African military award
• Spasmodic dysphonia
• Sudan Airways' IATA airline designator