The Saint Medard church of Saint-Mard, built between 1862 and 1867, is a triple-naved Neo-Romanesque building. It replaces an older 17th-century sanctuary. One of its vaults bearing the quarters of the de Laittres family is now part of the parish church of Rossignol.
Inside the Saint Medard church, one will notice the two 17th-century bye-altars. In the north altar one can admire a painting representing Simon Stock receiving the scapular from the hands of the Virgin, statues of Saint Hubert, Saint Nicholas and the Virgin and Child. The south altar is decorated with a picture of the Holy Trinity, the statues of Saint Medard, Saint Roch and Saint Sebastian.
Outside, above the church portal, stands the statue of Saint Medard blessing the faithful. Trauffier de Battincourt sculpted it from a block of Malmaison stone in 1867. Note that the saint gives his blessing with the left hand.
On the Easter Day of 2014 a carillon of 14 bronze bells was inaugurated.