Prudence (Latin: prudentia, contracted from providentia meaning "seeing ahead, sagacity") is the ability to govern and discipline oneself by the use of reason. It is classically considered to be a virtue, and in particular one of the four cardinal virtues (which are, with the three theological virtues, part of the seven virtues). Prudentia is an allegorical female personification of the virtue, whose attributes are a mirror and snake, who is frequently depicted as a pair with Justitia, the Roman goddess of Justice.

The word derives from the 14th-century Old French word prudence, which, in turn, derives from the Latin prudentia meaning "foresight, sagacity". It is often associated with wisdom, insight, and knowledge. In this case, the virtue is the ability to judge between virtuous and vicious actions, not only in a general sense, but with regard to appropriate actions at a given time and place. Although prudence itself does not perform any actions, and is concerned solely with knowledge, all virtues had to be regulated by it. Distinguishing when acts are courageous, as opposed to reckless or cowardly, is an act of prudence, and for this reason it is classified as a cardinal (pivotal) virtue.

In modern English, the word has become increasingly synonymous with cautiousness. In this sense, prudence names a reluctance to take risks, which remains a virtue with respect to unnecessary risks, but, when unreasonably extended into over-cautiousness, can become the vice of cowardice.

In the Nicomachean Ethics, Aristotle gives a lengthy account of the virtue phronesis (Ancient Greek: ϕρόνησις), traditionally translated as "prudence", although this has become increasingly problematic as the word has fallen out of common usage. More recently ϕρόνησις has been translated by such terms as "practical wisdom", "practical judgment" or "rational choice".