Cathedral Basilica of the Immaculate Conception in Castries

The Cathedral Basilica of the Immaculate Conception, located in Derek Walcott Square, Castries, Saint Lucia, is the seat of the Archbishop of the Roman Catholic Archdiocese of Castries, currently Robert Rivas. The cathedral is named after Mary, mother of Jesus, under her title, Our Lady of the Immaculate Conception.

The form "Cathedral", as it is commonly known, is the largest church in the Caribbean, measuring 200 ft long (61 m) by 100 ft wide (30 m) and was given the honorary status of a Minor Basilica on 11 May 1999 as part of the centenary celebrations.

The interior is decorated by a mural by St. Lucian artist Dunstan St. Omer.