Iglesia de Santa Bárbara, Iron church in Santa Rosalía, Mexico.

Iglesia de Santa Bárbara is a church building in Santa Rosalía with a complete metal construction featuring a steel frame and stamped sheet metal components throughout. The interior contains stained glass windows and religious imagery arranged within the metallic structure.

Originally designed for the 1889 Paris Exposition, the structure was later moved to Brussels before being acquired by the Boleo Mining Company. The company then had it reassembled and installed as a church for the mining settlement in Santa Rosalía.

The church is dedicated to Saint Barbara, patron saint of miners, a choice tied to the Boleo mine workforce. A memorial plaque placed on the building in 1987 recounts its history. Ownership passed from the French mining company to the Mexican community in 1954, when the local mine closed.

The building welcomes visitors during the day and continues to host religious services as an active place of worship. The metal structure is relatively small, making it easy to examine all architectural details while moving through the interior.

Tradition holds that the church was designed by Gustave Eiffel in 1884 and built in 1887, and that it won a prize at the 1889 Paris Exposition. In the early 1990s the American architecture student Angela Gardner examined the building and proposed the French architect Bibiano Duclos (1853–1925) instead; no blueprint or archive record confirms either name.