Bathing suits, also known as swimsuits, are worn for many purposes. Basically, for the general public, they are meant to avoid nudity or exposure when going for a swim or sun-bathing in public places like beaches and public swimming pools. Swimmers in a competition may wear them for thermal protection, and contestants in a beauty pageant, for displaying their bodies.

It is illegal to go swimming without a bathing suit in many parts of the United States, as it is considered to be a form of indecent exposure. There are special beaches and resorts reserved for people who wish to go nude while swimming. The number of nudist beaches has risen in recent years, and their popularity is still growing.

There are many types of bathing suits available for men, women and children. Mens bathing suits may include shorts, trunks, board shorts, jammers, speedo-style briefs, thongs, or cut-off jeans. Womens bathing suits mainly consist of one-piece swimsuits, bikinis, or thongs, with variants like monokinis, tankinis and string bikinis. Beaches mostly allow pants, underwear, or T-shirts to be used as make-shift bathing suits, but swimming pools seldom do so.

Special types of bathing suits or swimsuits, usually made from spandex, are generally worn by professional swimmers. They may wear full bodysuits, racer-back styles, jammers, and racing briefs for protection from drag, skin chaffing, stings and abrasion.

There are countless types, styles, designs and variants of bathing suits that have come up in recent years, and the number and popularity of certain styles are still growing.