Bondage, in the BDSM subculture, is the practice of consensually tying, binding, or restraining a partner for erotic, aesthetic, or somatosensory stimulation. A partner may be physically restrained in a variety of ways, including the use of rope, cuffs, bondage tape, or self-adhering bandage.

Bondage itself does not necessarily imply sadomasochism. Bondage may be used as an end in itself, as in the case of rope bondage and breast bondage. It may also be used as a part of sex or in conjunction with other BDSM activities. The letter "B" in the acronym "BDSM" comes from the word "bondage". Sexuality and erotica are an important aspect in bondage, but are often not the end in itself. Aesthetics also plays an important role in bondage.

A common reason for the active partner to tie up their partner is so both may gain pleasure from the restrained partner's submission and the feeling of the temporary transfer of control and power. For sadomasochistic people, bondage is often used as a means to an end, where the restrained partner is more accessible to other sadomasochistic behaviour. However, bondage can also be used for its own sake. The restrained partner can derive sensual pleasure from the feeling of helplessness and immobility, and the active partner can derive visual pleasure and satisfaction from seeing their partner tied up.