Petplay refers to consensual practices in which one participant takes on the persona, behaviour or headspace of a domestic companion animal — most often a dog, cat, rabbit or similar creature — while another may take a complementary role such as Handler, Owner or Caretaker. Petplay may be primarily erotic, primarily relational, ceremonial or purely playful, and often blends these registers.

Petplay in its modern form developed alongside the wider BDSM and Leather communities during the late twentieth century, drawing on earlier fetish photography, costume traditions and D/s roleplay. Puppy Play and Kitten Play emerged as distinct subcultures with their own gatherings, gear traditions and vocabulary.

Because Petplay covers such a wide range of expressions, communities sometimes disagree about which practices, gear or dynamics qualify. The Lexicon uses Petplay as an inclusive umbrella term.