San Romerio, Romanesque church on the Alp San Romerio in Brusio, Grisons, Switzerland

San Romerio is a church on a terrace at 1792 m above the Lago di Poschiavo, in the municipality of Brusio. It has an irregular rectangular nave, a nearly square choir with a semicircular arch dated 1659, and a bell tower on the north side. The floor is of rough stone slabs, the nave plaster is rough and the choir plaster smooth, and the roof is covered with local stone slabs.

The nave was built around 1055 beside a mule track between Tirano and Poschiavo, and the church is first documented in a purchase deed of 4 August 1055. In 1154 Bishop Ardizzone of Como confirmed that the community of "servitores ecclesiae sancti Romedhii" had received the Rule of St Augustine under his predecessor Guido Grimoldi (1096–1125). A papal decree of 27 September 1517 united San Romerio with Santa Perpetua in Tirano and the Madonna sanctuary, after which it served as a summer station for Valtellina clergy.

The annual procession from Tirano (about 400 m) climbed through vineyards, woods and alpine pastures to the church at 1792 m, and San Romerio long served as a summer station for Valtellina clergy. The name survives in the local dialect as San Rumedi, and the church is dedicated to Saint Remigius, a fourth-century hermit venerated above all in the Val di Non in Trentino.

San Romerio lies on the Via Valtellina long-distance trail, about four to five hours on foot from Poschiavo and roughly four hours down to Tirano. Other routes climb from Miralago and Le Prese on the Lago di Poschiavo. A PostBus or car road via Viano reaches a car park near the Maiensäss Piaz, leaving only about half an hour of walking to the church.

A local saying holds that anyone who walks a full circle around the chapel will never fall ill again. The joke works because the building stands right on the edge of a rock face dropping steeply to the valley floor, so no one can round it without falling.