Kornmarkt is located in the old town between Linsenstraße and Ratsstraße. It is dominated by the former Franciscan monastery church, whose monastery once extended north to the Schwemmnotte. The area between Felchtaer Straße and Walstraße was undeveloped until the monastery and town hall were built in the 13th century. Today's Kornmarkt became a cemetery for those Mühlhausen residents who felt that the Franciscan mendicant order provided better pastoral care than the priests of the Teutonic Order. The monks were buried in the monastery cloister north of the church.

After the Reformation was implemented in 1566, the cemetery served the remaining Catholics in the town until it was abolished in 1584. Grain was then traded there, which gave the cemetery its name. With the annexation of the imperial city by Prussia in 1802, the city scales were housed in the church and later grain floors were built in the nave and apartments in the choir. Two hotels and a bookshop characterized the Kornmarkt from the 19th to the 20th century. In the run-up to the 450th anniversary of the Peasants' War in 1975, the church was renovated and a Peasants' War Museum was housed in it, which led to an upgrading of the square. On the 500th anniversary of Thomas Müntzer's birth in 1989, the Kornmarkt was redesigned, with the base of the church portals being uncovered. In the early 1990s, the half-timbered building of the former Löwen pharmacy on the south side of the square was renovated and has since been used as a brewery pub, which has contributed significantly to the revitalization of the Kornmarkt.