| Basilica of Saint Pius X Basilique Saint Pie X (in French) | |
|---|---|
 View along the nave towards the central sanctuary. | |
| Religion | |
| Affiliation | Roman Catholic |
| Ecclesiastical or organizational status | Minor basilica |
| Year consecrated | 1958 |
| Location | |
| Location |  Lourdes |
| Geographic coordinates | 43°05′50″N 00°03′13″W / 43.09722°N 0.05361°W |
| Architecture | |
| Architect(s) | Pierre Vago, Eugene Freyssinet |
| Type | Church |
| Completed | 1957 |
| Construction cost | $5.6 million |
| Specifications | |
| Capacity | 25000 |
| Length | 191 metres (627 ft) |
| Width | 61 metres (200 ft) |
| Website | |
| Official website | |
The Basilica of Saint Pius X, informally known as the Underground Basilica, is a Catholic church and minor basilica in the town of Lourdes, France. It is part of the Sanctuary of Our Lady of Lourdes, a major pilgrimage site. The Basilica of St. Pius X is the largest of the sanctuary's churches. It was completed in 1958 in anticipation of the enormous crowds expected in Lourdes for the centenary of the Lourdes apparitions.