Basilica of the Immaculate Conception, Catholic church in Natchitoches Historic District, United States

The Basilica of the Immaculate Conception is a Catholic church in Natchitoches, Louisiana, begun in 1857 and completed between 1900 and 1905. It is the seventh building to house a parish founded in 1728 and served as cathedral of the Diocese of Natchitoches from 1853 until 1910. It was elevated to minor basilica in 2009.

The parish was founded in 1728, and its first church stood inside the walls of Fort St. Jean Baptiste between 1729 and 1733. The present building is the seventh; begun in 1857, it was delayed by the Civil War and Reconstruction and finished between 1900 and 1905. It served as cathedral of the Diocese of Natchitoches from 1853 until the see moved to Alexandria on August 6, 1910, and was named a minor basilica by Pope Benedict XVI on February 22, 2009.

The basilica serves as a center for traditional Catholic worship and houses the Bishop Martin Museum, which displays early church documents and sacred objects from the region.

The church stands at Front and Church Streets in the Natchitoches Historic District, within walking distance of the Cane River lakefront. It remains an active parish of the Diocese of Alexandria, so visitors should plan around Mass times rather than treat it as a museum. The present building was begun in 1857 and finished between 1900 and 1905.

The parish dates to 1728, and the present building is the seventh church on the site's succession of structures. It served as the first cathedral of the Diocese of Natchitoches, established by Pope Pius IX in 1853, until the see moved to Alexandria on August 6, 1910. Pope Benedict XVI raised it to minor basilica on February 22, 2009.