Bonastre (Catalan pronunciation: [buˈnastɾə]) is a municipality in the comarca of the Baix Penedès in Catalonia, Spain.

In 1178, Bernat de Papiol, who was lord of the place, donated it to the Monastery of St Cugat.

In 1382, King Pedro IV took possession of Bonastre for the crown although the monastery continued to govern the village until the 17th century.

In 1822, the town was attacked by a party of militia and was left deserted as its inhabitants fled to the surrounding mountains.

It consists of a single building covered by a cylindrical vault, with small interconnecting chapels at the side.