Église Saint-Maclou de Conflans-Sainte-Honorine, Gothic Catholic church in Conflans-Sainte-Honorine, France.

Église Saint-Maclou is a Gothic parish church of pale stone whose western facade ends in a pointed gable with a stone cross above a red-doored portal flanked by trefoil-traceried windows. A square tower with a clock marked "H. HUGUENIN" rises to the rear, carrying a stone spire rebuilt identically after lightning damage in 1927. Inside, a nave with round arches on wide piers and cream vaulting leads to a recessed pointed arch, an altar with a wooden crucifix and a blue-and-white statue.

The building's oldest sections come from the 12th century, when early Gothic features like pointed arches first appeared in its design. Over time, the structure evolved as additions and changes introduced fully developed Gothic elements throughout.

The name Saint-Maclou comes from the bishop of Paris, lord of the place, and may point to an origin around the end of the 10th century. The north side chapel was first dedicated to Saint Nicholas, patron of bargemen, then to Saint Honorine at the start of the 19th century; her relics had reached the town from Graville, probably in 876. Sunday morning masses are still held here.

The church stands on a limestone hill about forty metres above the Seine, with the river some sixty metres to the south. Its north aisle, west facade and whole south elevation open directly onto the public street, while the Place de l'Église, planted with trees, lies to the west and north. The Rue de la Procession descends from the Place Jules-Gévelot toward the quays.

Restoration efforts starting in 1995 uncovered hidden traces of the transition from Romanesque to Gothic building methods within the walls. These discoveries reveal how medieval builders gradually altered structural elements to match evolving architectural tastes.