São Miguel das Missões, Jesuit mission ruins in São Miguel das Missões, Brazil.

São Miguel das Missões is an archaeological site featuring the ruins of a sandstone church with eleven standing pillars and extensive foundations scattered across the terrain. The grounds also contain the remains of residential quarters and workshops where various crafts and daily activities took place.

Founded in 1687 under Spanish rule, São Miguel was the most notable of the Seven Peoples of the Missions. Its church was built between 1735 and 1750, and the settlement was a centre of the Guaranitic War before being burned and depopulated in 1756. Partially restored, it declined after the Jesuits' expulsion and was looted in the early 19th century.

The Mission Museum displays works created by Guaraní artisans during the colonial period, featuring religious sculptures that reflect their artistic contribution. These pieces show how indigenous craftspeople participated in and shaped the spiritual life of the settlement.

The site welcomes visitors throughout the year and offers guided tours to help understand the archaeological remains and their historical context. An on-site museum provides additional insight into the artifacts and works created during the settlement's active period.

The site was listed by IPHAN in 1938 and named a UNESCO World Heritage Site in 1983, together with the Argentine ruins of San Ignacio Miní, Santa Ana, Loreto and Santa María la Mayor. In 2015 IPHAN also granted it the status of Brazilian Cultural Heritage for its ties to Guaraní history and spirituality.