Cathedral Basilica of the Immaculate Conception, Catholic cathedral in downtown Mobile, United States.

The Cathedral Basilica of the Immaculate Conception is a Catholic church in downtown Mobile featuring Greek Revival architecture. The building stands out for its two towers reaching approximately 103 feet (31 meters) in height, eight massive columns, and decorated stained glass windows.

Construction began in 1835 based on architect Claude Beroujon's design, with the first services held in 1850. Financial difficulties delayed the project during its early phases.

The parish, founded in 1703, is the oldest on the Gulf Coast; it was first called Notre Dame de la Mobile and took the name Immaculate Conception in 1781 under Spanish rule. The twelve main stained glass windows, six per side wall, were made by Franz Mayer & Co. of Munich and installed between 1890 and 1910; each shows an episode from the life of the Virgin.

The cathedral stands on South Claiborne Street, bounded by Dauphin Street to the north, Franklin Street to the west and Conti Street to the south. Its front faces east toward the Mobile River and overlooks Cathedral Square. The building runs 164 ft (50 m) east to west and is 90 ft (27 m) wide.

The stained glass windows were created in Munich between 1890 and 1910 and depict scenes from Mary's life. Each window tells a story spanning from the moment of her Immaculate Conception to the Crucifixion of Jesus.