セイヨウキンシバイ（西洋金糸梅）とはオトギリソウ科の植物の一種。学名Hypericum calycinum。別名ヒメキンシバイ（姫金糸梅）。学名のカタカナ表記のヒペリカム・カリシナムで呼ばれることが多い。
小アジア原産の常緑小低木で枝は垂れ、地下茎を伸ばして繁殖していく。花期は6～7月頃で黄色の花を咲かせる。本種は名前がセイヨウキンシバイまたはヒメキンシバイであるので、花が同属植物のキンシバイに似ていそうであるが、あまり似ていない。それより同属のビヨウヤナギの方が本種と花がよく似ている。グランドカバーとして栽培されることが多い。
Hypericum calycinum is a species of prostrate or low-growing shrub in the flowering plant family Hypericaceae. Widely cultivated for its large yellow flowers, its names as a garden plant include Rose-of-Sharon in Britain[2] and Australia, and Aaron's beard, Great St-John's wort, and Jerusalem star. Grown in Mediterranean climates, widely spread in the Strandja Mountains along the Bulgarian and Turkish Black Sea coast.
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, semi-evergreen garden shrub with many named cultivars and hybrids derived from it.