Basilica of Saint-Martin d'Ainay, Romanesque minor basilica in 2nd arrondissement of Lyon, France

The Basilica of Saint-Martin d'Ainay is a Romanesque church in the 2nd arrondissement of Lyon, France, classed as a monument historique and raised to minor basilica in 1905. Its pale beige stone facade carries two square towers: the left one with a pointed pyramidal roof and a cross, the right one higher, with rows of arched openings. The nave is 17 metres wide and the whole structure 37 metres long.

The church was built on the site of a Benedictine priory founded in the 9th century, and the current building was completed toward the end of the 11th century. Pope Paschal II consecrated it shortly after 1100, an event that gave the site lasting standing in the region.

The name of the church honors Saint Martin of Tours, one of the most venerated figures in early Christianity. Inside, visitors can see mosaics and paintings added over many centuries, giving the walls a layered, accumulated feel.

The church stands on Place d'Ainay in the 2nd arrondissement and is easy to reach on foot from the city center. It is worth timing a visit outside of religious services if you want to move around and look at the architecture without interruption.

The church keeps a medieval mosaic found in 1851 near the main altar, showing an ecclesiastic holding a model of the church. It is the only medieval mosaic discovered in Lyon in the 19th century, restored in 1852–1855 and again in 1934. Mosaics found in the Sainte-Blandine chapel in 1844–1845 were destroyed.