A bathtub fetish, also known as balneophilia or bathing fetish, refers to a sexual attraction or arousal linked to activities involving bathtubs, baths, or bathing. Individuals with this fetish may experience sexual excitement or gratification through various aspects of bathing, such as taking baths, watching others bathe, or participating in bath-related activities.

For some people, the fetish may involve a fascination with the sensations, textures, and smells associated with water, soap, and bathing products. Others may find the enclosed space of a bathtub, the intimacy of washing oneself or others, or the sight of a naked body in water particularly arousing. Additionally, the sound of running water or the feeling of being immersed in warm water may contribute to the erotic appeal of bathtub-related activities.