Church of the Assumption of Our Lady and Saint John the Baptist, Gothic cathedral in Kutná Hora, Czech Republic

The Church of the Assumption of Our Lady and Saint John the Baptist is a former Cistercian convent church in Sedlec, about 2 km northeast of Kutná Hora's centre. Its five-aisled cathedral-type plan with a three-aisled transept, polygonal choir and ring of chapels reaches 87 m in length; the main nave rises well above the side aisles. Santini's west front adds long corner buttresses with finials and a hexagonal portico with three canopies.

The Gothic church was built between 1280 and 1320 under Abbot Heidenreich, replacing a Romanesque church destroyed in the late 13th century. Hussite troops burned it with the monastery in 1421, and it stood ruined for over two centuries. Abbot Jindřich Snopek funded the rebuilding from 1700, completed by Santini-Aichel and consecrated in 1708.

The church is dedicated to the Assumption of Our Lady and Saint John the Baptist, and its name recalls the Cistercian abbey founded in 1142, whose monks came from Waldsassen in Bavaria. Santini gave the interior a green colour scheme so that the whole space would resemble a spring meadow, and the star shape recurring in the vault ribs and the presbytery paving stands for the Virgin Mary.

The church stands in Sedlec, about 2 km northeast of Kutná Hora's centre, and is visited together with the Sedlec ossuary nearby. The eastern part with choir, chapels and transept keeps its medieval exterior, while the west front carries Santini's 1700s portico. A restoration was carried out in 2001.

Architect Jan Santini-Aichel developed an innovative approach during the 18th-century redesign, merging Gothic and Baroque styles in ways that most churches of that era did not attempt. This architectural fusion at the cathedral remains uncommon among European religious buildings.