3S

3S may refer to:
 * 3S, for single, seventies/1970s, stuck, a slang form of sheng nu, a derogatory Chinese term referring to unmarried women in their mid to late twenties
 * 3S gondola lift
 * 3-S treatment, a method for dealing with unwanted or unwelcome animals in rural areas
 * 3S, a series of Toyota S engines
 * Air Antilles Express IATA airline designator
 * 3S Supersonic gas separation, a brand name for a gas processing technology
 * The S line of the Mazda3 automobile
 * Threes (video game)
 * In Geoinformatics, 3S means the combination of~
 * Geographic information system
 * Global Positioning System
 * Remote sensing