A milk bath is a bath which contains milk, typically in a powdered form which hydrates as it settles. People have been bathing in milk for centuries to improve their skin; historically, people believed that milk made skin whiter and firmer. Milk baths also help to clean the skin, provide natural exfoliation, and tend to soften and smooth the skin, especially when milk baths are undertaken on a regular basis.

Cleopatra is probably the most notable historical figure who used a milk bath, allegedly submerging herself in a bath of milk and honey on a regular basis. Numerous other historical figures used milk baths for skin care, including men, and the practice continues to be quite popular. Numerous spas offer milk bath treatments, and it is also possible to purchase milk bath mixtures for use at home; making your own milk bath is generally quite easy as well.

Although a milk bath can be made with straight milk, typically other ingredients are added. Oatmeal, honey, essential oils, and flowers may be added, with scents like lavender calming the bather, while orange energizes. Some milk baths are also mixed with clays which have skin benefits. Generally, a milk bath is very mild, making it suitable for all skin types, and it is followed with a shower to rinse off and a coating of moisturizer to seal in the benefits of the milk.

While one could simply dump warmed milk into a bathtub, this can get messy and awkward. Most people prefer to use powdered milk, sprinkling the milk slowly into the water as the bath fills. To ensure even mixing, a milk bath mixture can be blended with a small amount of water in a large bowl and then poured into the tub; this eliminates the tendency to clump, ensuring that all of the milk is fully dissolved.

The ideal milk bath is lukewarm, and people generally should not stay in for more than 10 minutes or so, or the natural acids in the milk which help to condition the skin can start to cause irritation. If essential oils are used in a milk bath, bathers should be alert to the early signs of irritation, such as tingling, itching, or blotchy, raised skin, as sometimes people can have peculiar reactions to essential oils.

When people take a milk bath at home, cleanup is important. Spas typically rely on industrial-strength cleaning agents to wipe out their treatment tubs after use, and a solvent like rubbing alcohol applied after a washing can also help to cut down on residue, ensuring that the bathroom doesn't smell like moldering milk for months on end.