A lotion is a low-viscosity topical preparation intended for application to unbroken skin. By contrast, creams and gels have higher viscosity.

Lotions are applied to external skin with bare hands, a brush, a clean cloth, cotton wool, or gauze. While lotion may be used as a medicine delivery system, many lotions, especially hand lotions and body lotions are meant instead to simply smooth, moisturize and soften the skin. These may be used in anti-aging lotions, which can also be classified as a cosmetic in many cases, and may contain fragrances. The Food and Drug Administration voiced concern about lotions not classified as drugs that advertise anti-aging or anti-wrinkle properties.