The Old World monkeys or Cercopithecidae are a family of primates, the only family in the superfamily Cercopithecoidea in the clade (or parvorder) of Catarrhini.

The Old World monkeys are native to Africa and Asia today, inhabiting a range of environments from tropical rain forest to savanna, shrubland and mountainous terrain, and are also known from Europe in the fossil record. However, a (possibly introduced) free-roaming group of monkeys still survives in Gibraltar (Europe) to this day. Old World monkeys include many of the most familiar species of nonhuman primates, such as baboons and macaques.