Notre-Dame-des-Marais, Gothic church in La Ferté-Bernard, France.

Notre-Dame-des-Marais is a Gothic church of pale stone in La Ferté-Bernard, its south side and chevet ringed by flying buttresses and pinnacled buttresses. A square tower with a lead-covered spire rises to 50 m, and the choir vaults reach 25 m, nearly level with the tower top. The nave and transept vaults stay below 17 m.

A chapel dedicated to Notre-Dame is first recorded in 1233 and became a parish church in 1366. The Hundred Years' War delayed the new building, begun around 1450 with the nave and the square tower; the choir and its ring of chapels followed in the early 16th century. The church was completed in 1596, when the Viet brothers closed the high choir vaults, as an inscription above the triumphal arch records.

The oldest windows date from the second half of the 15th century and fill the nave and the north choir aisle; the choir chapel and south aisle windows were made between 1533 and 1540. Inscriptions name donors and glaziers: the Supper in the House of Simon was given by the Quelain family and executed by Jehan Courtois in 1534. The south balustrade carries the hymn Regina Coeli.

The main entrance is on the south side, facing Place Carnot, not the west front, which opens onto a dead-end lane. The church stands on drained marshland in the town centre, and the paved square around it is used for parking. The building is classified as a monument historique, so visits may coincide with restoration work.

The church organ dates from 1532 and features two keyboards with pedals. It was later modified by Pierre Bert, an organ builder who also worked on Le Mans Cathedral.