Washing is a method of cleaning, usually with water and often some kind of soap or detergent. Washing both body and clothing is an essential part of good hygiene and health.

Often people use soaps and detergents to assist in the emulsification of oils and dirt particles so they can be washed away. The soap can be applied directly, or with the aid of a washcloth.

People wash themselves, or bathe periodically. Infants, the sick, and people with disabilities are bathed by a caregiver, but those that can wash themselves often do so. Often a shower or a bathtub is used for washing. People bathe naked under most circumstances, and commonly do so in the privacy of their home.

In Europe, some people use a bidet to wash their external genitalia after using the toilet, as opposed to using toilet paper.

More frequent is washing of just the hands, e.g. before and after preparing food and eating, after using the toilet, after handling something dirty, etc. Hand washing is important in reducing the spread of germs. also common is washing the face, which is done after waking up, or to keep oneself cool during the day. Brushing one's teeth is also essential for hygiene and is a part of washing.

In photography, washing is an important part of all film processing and printmaking processes. After materials have been fixed, washing removes unwanted and exhausted processing chemicals which, if left in situ, may cause deterioration and destruction of the image.

A disadvantage of the use of thiosulfate as a fixer is its ability to dissolve elemental silver at a very slow rate. If films or papers are inadequately washed after fixing, any residual fixer can slowly bleach or stain the photographic image. For prints on high grade fibre papers, a period of continuous washing in clean, cold water for up to 40 minutes may be required. For modern plastic (resin) coated papers, washing for as little as 2 minutes in warm water can be sufficient to eliminate residual fixer. Washing aids (also called hypo clearing agents) can be used to make the process of removing fixer faster and more thorough.

A quick, water-saving, and archival technique for washing film fixed with nonhardening fixer in a spiral tank is the popular "Ilford method":