A Lourdes grotto is a replica of the grotto where the Lourdes apparitions occurred in 1858, in the town of Lourdes in France, now part of the sanctuary of Our Lady of Lourdes. Some Lourdes grottos are almost identical reproductions of the scene of the apparitions, with statues of Our Lady of Lourdes and Bernadette Soubirous in a natural or artificial cave, while others may differ from the original in size, shape or style.

A grotto is a natural or artificial cave used by humans in both modern times and antiquity, and historically or prehistorically. Naturally occurring grottoes are often small caves near water that are usually flooded or often flooded at high tide. Sometimes, artificial grottoes are used as garden features. The Grotta Azzurra at Capri and the grotto at Tiberius' Villa Jovis in the Bay of Naples are examples of popular natural seashore grottoes.