Water retention can refer to:
Water retention (medicine), an abnormal accumulation of fluid in the circulatory system or within the tissues or cavities of the bodyEdema, an abnormal accumulation of fluid beneath the skin, or in one or more cavities of the body Premenstrual water retention, a common phenomenon associated with the menstrual cycleWater retention curve, relationship between soil water content and water pressure head Water retention on mathematical surfaces, topographic surfaces with basins