Mendicant orders are, primarily, certain Catholic Christian religious orders that have adopted a lifestyle of poverty, traveling, and living in urban areas for purposes of preaching, evangelization, and ministry, especially to the poor. At their foundation these orders rejected the previously established monastic model. This model prescribed living in one stable, isolated community where members worked at a trade and owned property in common, including land, buildings and other wealth. By contrast, the mendicants avoided owning property at all, did not work at a trade, and embraced a poor, often itinerant lifestyle. They depended for their survival on the goodwill of the people to whom they preached.

The term "mendicant" is also used with reference to some non-Christian religions to denote holy persons committed to an ascetic lifestyle, which may include members of religious orders and individual holy persons.