Balloon flowers (Platycodon grandiflorus) are clump-forming perennials and members of the easy-to-grow bellflower family of plants although the blooms do not resemble bells. Instead, puffy, balloon-like buds swell up to produce the 2- to 3-inch star-shaped flowers. This easy-grower blooms all summer long with intense blue-violet flowers, but there are also cultivars with white and pink blooms. Balloon flowers are generally planted in the spring after the danger of frost has passed, growing quickly to bloom in the first year.

Platycodon grandiflorus (from Ancient Greek πλατύς "wide" and κώδων "bell") is a species of herbaceous flowering perennial plant of the family Campanulaceae, and the only member of the genus Platycodon. It is native to East Asia (China, Korea, Japan, and the Russian Far East). It is commonly known as balloon flower (referring to the balloon-shaped flower buds), Chinese bellflower, or platycodon.

This plant is hardy down to −40 °C (−40 °F) and can be cultivated in USDA zones 3A to 9b. It dies down completely in winter, reappearing in late spring and flowering in summer. However, plants are widely available from nurseries in full flower from April onwards.