Sempervivium calcareum, the houseleek, is a species of flowering plant in the stonecrop family Crassulaceae, native to the southern Alps in Europe.

An evergreen succulent perennial, it has a rosette with thick leaves that store water.

This plant reproduces with asexual budding and monocarpic sexual reproduction.

[2] Sempervivum calcareum is cultivated as an ornamental garden plant.

The cultivars 'Extra',[3] 'Guillaumes'[4] and 'Sir William Lawrence'[5] have gained the Royal Horticultural Society's Award of Garden Merit.