Saint-Guibert church is the former abbey church for the Benedictine abbey in Gembloux. Founded in 940 by the knight Wicbertus (later known as St Guibert). The current building was constructed between 1762 and 1779 by Laurent-Benoit Dewez, a famous architect from the Austrian Low Countries, after a fire in 1678 that not only ravaged the abbey, but also the town. After the secularisation of possessions and the abolition of religious orders, the abbey was sold in 1797. The abbey church then became a parish church in 1812 to replace the old parish church situated in Rue des Abbés Comtes. The building was originally in the shape of a cross, but was extended with a square and raised between 1885 and 1886 in order to form a nave. Today, the secular buildings of the abbey have been annexed by the Agronomy Faculty of Gembloux (University of Liège – Gembloux Agro-bio Tech).
Built in brick and stone, with a limestone base, the church has a nave with three bays, a prominent transept and chancel with flat chevet. The façade features an arched doorway built from the original structure. The door has a foliage keystone and is topped by a triangular pediment.
The nave and its three spans have convex trapezoid openings and keyed arched windows. It features Corinthian pilasters supporting an entablature with cornices and modillions. The roof of the nave is hipped slate bâtière. The crossing is topped by a 19th-century pinnacle flanked to the east by a tower with domed roof and skylight. The prominent transept has a low inscribed chest in its four corners. The crossing is topped by a blind dome and barrel vaulting. The chancel still houses the monks' stalls.