4S

4S may refer to:

Places

 * 4S Ranch, California, an unincorporated community in San Diego County

Other uses

 * iPhone 4S, the 5th generation of the iPhone
 * Scandinavian Simvastatin Survival Study, a multicenter clinical trial that was performed in 1990s in Scandinavia
 * Society for Social Studies of Science, a non-profit scholarly association devoted to the social studies of science and technology
 * Toshiba 4S, a nuclear reactor
 * Toyota S engine
 * DS 4S, a car
 * 4S, the production code for the 1977 Doctor Who serial The Talons of Weng-Chiang