STD may refer to:
- Sexually transmitted disease
- Subscriber trunk dialling, also known as subscriber toll dialling, allowing subscribers to dial trunk calls without operator assistance.
- Doctor of Sacred Theology (Sacrae Theologiae Doctor)
- São Tomé and Príncipe dobra, the ISO 4217 code for the currency of São Tomé and Príncipe
- Sunbeam-Talbot-Darracq, one of the many incarnations of the Sunbeam Car Company
- Grupo Santander, The New York Stock Exchange symbol
- Schaffer The Darklord, a nerdcore rapper from Queens, New York.
- C++ Standard Library
- STD, followed by an integer, is a designation of an RFC that has been accepted as an Internet Standard
- Stroud railway station (National Rail code) in Stroud, Gloucestershire, England
- Scheduled Time of Departure, the time advertised by an airline (or other transport company) as the time a flight (or other form of transport) is due to start its journey.
- std, the set direction flag instruction on x86 compatible CPUs, opposite of cld
- Mayor Buenaventura Vivas Airport, in Santo Domingo, Venezuela (IATA code STD)
- Internet Standard, abbreviated as STD, e.g. "STD 1"