Église Notre-Dame de Calais, Gothic church in Calais, France

Notre-Dame de Calais is built in the shape of a Latin cross, 90 m long and 45.5 m wide, with a nave and aisles, north and south transepts, a choir with choir-aisles and a side chapel. Its walls are of Boulogne stone and sand brick, and a 56 m square lantern tower with four corner pinnacles and a slate spire rises over the crossing. The building's axis tilts noticeably to the north-east.

A first church, rectangular with two facade towers, stood on the site of today's transept in the early 13th century. Damaged in 1346–47 during the Hundred Years' War, it was rebuilt and enlarged under English rule from the later 14th to the 16th century, with Flemish builders raising the nave's upper parts, choir and tower in sand brick. After Calais returned to France in 1558 it became the town's main church, and the 56 m tower served the 1784–1790 Anglo-French Survey.

The name Notre-Dame refers to the Virgin Mary, to whom the church is dedicated. The choir's high altar, carved in polychrome marble and stone from 1624 to 1629 by the Flemish sculptor Adam Lottmann, holds Gerard Seghers' Assumption of the Virgin, restored in 2005. The Descent from the Cross, long thought to be by Rubens, is now attributed to Pieter Van Mol.

The church stands on Rue de la Paix, and the building's axis leans noticeably toward the north-east. The south door, the Porte Saint-Jacques, is walled up because buildings were put up on the former cemetery, closed in 1794; the north Porte Saint-Pierre opens onto the north transept, the oldest part, with walls of Boulogne stone 1.60 m thick. The west portal was pierced in the 18th century.

The tower served as an observation point for the Anglo-French Survey of 1784–1790, which used trigonometry to measure the distance between the Paris and Greenwich observatories. Cross-Channel sightings of signal lights at Dover Castle and Fairlight Down were made in September and October 1787. A gallery below the spire served as a walkway until 1846, and on clear days Dover Castle can be seen from it.