"Fortune favours the bold" or "fortune favours the brave" are among the English translations of the Latin proverb "audentes Fortuna iuvat" and its variations. The phrase has been widely used as a slogan in the Western world to emphasize the rewards of courage and bravery, particularly within military organizations, and it is also used up to the present day on the coats of arms of numerous families and clans. It has historically served as a popular motto for universities, along with other academic institutions and recreational associations.

Fortune favours the bold is the translation of a Latin proverb, which exists in several forms with slightly different wording but effectively identical meaning, such as:

This last form is used by Turnus, an antagonist in the Aeneid by Virgil. Fortuna refers to luck and to the Roman goddess who was its personification.

Another version of the proverb, fortes Fortuna adiuvat, 'fortune favours the strong/brave', was used in Terence's 151 BCE comedy play Phormio, line 203. Ovid extends the phrase at I.608 of his didactic work, Ars Amatoria, writing "audentem Forsque Venusque iuvat" or "Venus, like Fortune, favors the bold."

Pliny the Younger quotes his uncle, Pliny the Elder, as using the phrase Fortes fortuna iuvat when deciding to take his fleet and investigate the eruption of Mount Vesuvius in CE 79, in the hope of helping his friend Pomponianus: "'Fortes' inquit 'fortuna iuvat: Pomponianum pete.'" ("'Fortune', he said, 'favours the brave: head for Pomponianus.'") Pliny the Elder ultimately died during the expedition.

The Latin phrase Fortuna Eruditis Favet ("fortune favours the prepared mind") is also used. Louis Pasteur, the French microbiologist and chemist, expressed this as: "Dans les champs de l'observation le hasard ne favorise que les esprits préparés", meaning "In the fields of observation, chance favours only the prepared minds."

In The Prince, Niccolò Machiavelli remarked, "It is better to be adventurous than cautious," but extending the metaphor, "because fortune is a woman and . . . it is necessary to beat and ill-use her; and it is seen that she allows herself to be mastered by the adventurous."

The proverb may be a rewording of a line by Democritus that "boldness is the beginning of action, but fortune controls how it ends" (Ancient Greek: Τόλμα πρήξιος αρχή, τύχη δε τέλεος κυρίη, romanized: Tólma préxios arché, túche de téleos kuríe).