Passiflora, known also as the passion flowers or passion vines, is a genus of about 550 species of flowering plants, the type genus of the family Passifloraceae.

They are mostly tendril-bearing vines, with some being shrubs or trees. They can be woody or herbaceous. Passion flowers produce regular and usually showy flowers with a distinctive corona. Passiflora has a largely neotropic distribution, unlike its family Passifloraceae, which includes more Old World species (such as the genus Adenia). The vast majority of Passiflora are found in Mexico, Central and South America, although there are additional representatives in the United States, Southeast Asia, and Oceania.

A number of species of Passiflora are cultivated outside their natural range for both their flowers and fruit.