Église Saint-Nicaise de Rouen, Gothic church in Saint-Marc district, Rouen, France

Saint-Nicaise is a pale grey stone Gothic church in Rouen whose west front has a tall, narrow tower with a pointed spire and, to its right, a steep gabled facade with three pointed portals, a rose window and flanking pointed windows. The dark slate roof carries a small central flèche. The nave and bell tower were rebuilt in reinforced concrete by Pierre Chirol and Émile Gaillard from 1934 to 1937, with a single tall nave lit by Max Ingrand's windows and four concrete arches supporting a luminous dome.

Founded in 640 by Saint Ouen as a chapel outside the city walls, it held the relics of Saint Nicaise brought from Gasny. It became a parish church in 1388, with its priest appointed by the abbot of Saint-Ouen, and a new choir was built from 1538 to 1561. Calvinists pillaged it in 1560. On 10 March 1934 a fire starting on the north side of the nave partly destroyed it; Pierre Chirol and Émile Gaillard rebuilt the nave and bell tower in reinforced concrete between 1934 and 1937, and the church was blessed again on 13 October 1940.

The parish takes its name from Saint Nicaise, whose relics Ouen, archbishop of Rouen, brought from Gasny to the chapel he founded in 640. The church kept a 1636 pulpit and a 1634 organ by Crépin Carlier, restored and inaugurated on 24 October 1928 by organist Joseph Bonnet. From the 1990s the archbishop of Rouen, Mgr Duval, assigned it to the traditional rite.

The church stands on Rue Saint-Nicaise and is accessible by bus lines F2, 15, and 22, with the closest stop at Saint-Vivien. Visitors should check current access conditions before planning a visit.

In 2016 activists of Nuit debout occupied the deconsecrated church, cleaning the floor and shoring up fragile artworks, and demanded that residents be consulted on its future; they were expelled on 6 June. The association La Boise de Saint-Nicaise was then created to promote the building and study possible conversions.