A bidet (UK: /ˈbiːdeɪ/, US: /bɪˈdeɪ/ ^ⓘ) is a bowl or receptacle designed to be sat upon in order to wash a person's genitalia, perineum, inner buttocks, and anus. The modern variety has a plumbed-in water supply and a drainage opening, and is thus a plumbing fixture subject to local hygiene regulations. The bidet is designed to promote personal hygiene and is used after defecation, and before and after sexual intercourse. It can also be used to wash feet, with or without filling it up with water. Some people even use bidets to bathe babies or pets. In several European countries, a bidet is now required by law to be present in every bathroom containing a toilet bowl. It was originally located in the bedroom, near the chamber-pot and the marital bed, but in modern times is located near the toilet bowl in the bathroom. Fixtures that combine a toilet seat with a washing facility include the electronic bidet.

Opinions as to the necessity of the bidet vary widely over different nationalities and cultures. In cultures that use it habitually, such as parts of Western, Central and Southeastern Europe (especially Italy, Portugal, Spain, France and Turkey), Eastern Asia and some Latin American countries such as Argentina, Uruguay or Paraguay, it is considered an indispensable tool in maintaining good personal hygiene. It is commonly used in North African countries, such as Egypt. It is rarely used in sub-Saharan Africa, Northwestern Europe, Australia, and North America.

Bidet is a French loanword meaning 'pony' due to the straddling position adopted in its usage.

Bidets are primarily used to wash and clean the genitalia, perineum, inner buttocks, and anus. Some bidets have a vertical jet intended to give easy access for washing and rinsing the perineum and anal area. The traditional separate bidet is like a wash-basin which is used with running warm water with the help of specific soaps, and may then be used for many other purposes such as washing feet.

A bidet shower (also known as "bidet spray", "bidet sprayer", or "health faucet") is a hand-held triggered nozzle, similar to that on a kitchen sink sprayer, that delivers a spray of water to assist in anal cleansing and cleaning the genitals after defecation and urination. In contrast to a bidet that is integrated with the toilet, a bidet shower has to be held by the hands, and cleaning does not take place automatically. Bidet showers are common in countries where water is considered essential for anal cleansing.

Drawbacks include the possibility of wetting a user's clothing if used carelessly. In addition, a user must be reasonably mobile and flexible to use a hand-held bidet shower.

A bidet is a plumbing fixture that is installed as a separate unit in the bathroom besides toilet, shower and sink, which users have to straddle. Some bidets resemble a large hand basin, with taps and a stopper so they can be filled up; other designs have a nozzle that squirts a jet of water to aid in cleansing.

There are bidets that are an integrated part of the toilet. Having a nozzle (fixed or movable) that is designed to spray water at the anus, and often also (separately) the genitals. Some have separate nozzles, for anus and genitals. The nozzle is typically at the back of the toilet rim.