Panties (in American English, also called pants, undies or knickers in British English) are a form of underwear primarily worn by women. Panties can be form-fitting or loose. Typical components include an elastic waistband, a crotch panel to cover the genitalia (usually lined with absorbent material such as cotton), and a pair of leg openings that, like the waistband, are often made of elastic. Various materials are used, but are usually chosen to be breathable.

In the United Kingdom, Ireland, South Africa, Malaysia, Singapore and occasionally in other Commonwealth countries such as Australia^[1][2] and New Zealand, panties may be referred to as "undies" or "knickers"; "knickers" can also refer to male underwear, while "panties" generally refers only to female underwear. In Australia, men's underpants are often referred to as "undies",^[3] although the word can also refer to women's underpants. The term is little used in the United States and Canada, where the term "panties" is usually favoured. In the UK, the term "pants" is also used for both men's and women's underwear (not to be confused with the North American usage of "pants", referring to what both Americans and the British call "trousers" — although "pants" is also used in some parts of Northern England). Both men's and women's underwear is also sometimes referred to as "drawers". In any context, "drawers" suggests underwear that is dowdy, not fashionable or attractive.

Panties are classified into various styles based on criteria such as the amount of rear coverage, width at the sides and height at which they are worn.

These categories are not necessarily distinct and usage may vary somewhat among brands:^[4]

Panties are made of a variety of materials, including cotton, lace, latex, leather, lycra, mesh, nylon, PVC, polyester, rawhide, satin, and silk. Construction typically consists of two pieces (front and rear) that are joined by seams at the crotch and sides; an additional gusset is often in the crotch, with the waistband and leg-openings made from elastic.

Boy shorts or boyshorts, also known as boy short panties, boys' cut, booty shorts, shorties, or boyleg briefs are a kind of women's underwear that covers the hips, named for their similarity to boxer briefs, a variation on boxer shorts. Some resemble men's briefs, complete with fly and contrast trim. Unlike men's briefs, this style is usually lower cut. Boy shorts often cover most of the buttocks.^[6][7]

Boy shorts have become a popular choice, since they avoid displaying a prominent visible panty line, and are a modest and comfortable alternative to thongs and conventional panties. They are also popularly matched with a camisole top and worn as loungewear. Cotton-spandex blends and lace are the most popular materials for boy shorts. The term boy shorts can also refer to bathing suit bottoms in the same style.^[6]

The earliest known use of underwear that resembles modern panties dates back to 4,400 B.C. during the Badari period in Egypt.^[8]