A Head shop is a store that sells goods related to illegal drugs and their consumption, such as bongs, roach clips, pipes, rolling papers, blacklight-responsive posters, incense, cigarette lighters, products claimed to give false negative results for drugs on urine analysis tests, whipped-cream chargers (which contain nitrous oxide), et cetera.

The term "head shop" comes from the term "head" for a user of recreational drugs. This word is most commonly encountered in compound words such as "pothead" (user of cannabis), "cokehead" (user of cocaine), etc, used to describe devotees of particular drugs. This usage has also been adapted to describe ardent fans of certain bands, in particular "deadheads" (fans of the Grateful Dead), or "phishheads" (fans of Phish).

In the United States of America head shops exist in a legal grey area because of the nature of the materials they sell, especially devices like bongs or glass pipes. Because of this most head shops have rules concerning the naming of the equipment. Patrons are forbidden from calling a bong by its proper name for instance; instead they must refer to it as a water pipe or hookah. It is believed that the Drug Enforcement Administration or other police forces do not have authority to arrest owners who sell devices used to ingest tobacco, hence the renaming. In most cases if a patron refers to a bong as a bong they will be warned or removed from the store in an effort for the store owner to demonstrate they are not selling products used for ingestion of cannabis. Similarly any speaking of cannabis or other illegal drugs is not allowed.