4S

A number of things are known by the acronymn 4S, including:
* 4S Ranch, California, an unincorporated community in San Diego County
* Scandinavian Simvastatin Survival Study, a multicenter clinical trial that was performed in 1990s in Scandinavia
* Society for Social Studies of Science, an academic organization
* a series of Toyota S engines
* the Toshiba 4S nuclear reactor