Hypericum calycinum, commonly called the Rose of Sharon, is a shrubby species of Hypericum, family Clusiaceae, noted for its much larger flowers than most other species in the genus. It is a low, creeping, woody shrub to about 1 m tall and 1-2 m wide but often smaller. The green, ovate leaves grow in opposite pairs. The solitary flowers are 3-5 cm in diameter, a rich yellow, with five petals, and numerous yellow stamens. It is indigenous to southeast Europe and southwest Asia. It is a popular evergreen garden shrub, with many named cultivars and hybrids derived from it, e.g. Hypericum 'Hidcote', in the photograph, top right.

Other common names are: Aaron's beard, Great St-John's wort, Jerusalem star.

The name Rose of Sharon is also sometimes confusingly applied to an entirely unrelated species, Hibiscus syriacus.