A sex toy is an object or device that is primarily used in facilitating human sexual pleasure. This term can also include BDSM apparatus, sex furniture, sling, or angled cushions and shaped pillows. The most popular sex toys are designed to resemble human genitals and can be classified as vibrating or non-vibrating. Sex toys usually does not usally apply to items such as contraceptives, pornography, or condoms.

A related term may be adult toy or more generally, marital aid, although marital aid is broader as it can also be applied to drugs and herbs marketed as supposedly enhancing or prolonging sex.

In many areas, such as some U.S. Southern states, the sale of sex toys is discouraged, or outlawed completely, by laws prohibiting or regulating "obscene devices". As recently as 1999, William H. Pryor, Jr., an assistant attorney general in Alabama commenting on a case involving sex toys and discussing to what end the devices are used, was quoted as saying there is no "fundamental right for a person to buy a device to produce orgasm". A federal appeals court upheld Alabama's law prohibiting the sale of sex toys on Valentine's Day, 2007.

In February 2008, a federal appeals court overturned a Texas statute banning the sales of sex toys, deeming such a statute as violating the Constitution's 14th Amendment on the right to privacy. The appeals court cited Lawrence v. Texas, where the U.S. Supreme Court in 2003 struck down bans on consensual sex between gay couples, as unconstitutionally aiming at "enforc[ing] a public moral code by restricting private intimate conduct".

There are organizations that assist those who sell sex toys to stay within legal limits and provide them with news, legal updates and assistance. One such organization is the National Association for Sexual Awareness & Empowerment (NASAE)

Sex toys and lubricants, have become increasingly available in major commercial retail outlets in the United States as of 2007 and early 2008. On-shelf displays tend to be more discreet than the offerings on the major outlet web sites. These items tend to be displayed in the female health sections of stores.