The Church of St. Nicholas in Zamość is a Renaissance-Baroque temple from the 17th century, located in the Old Town, which was previously a Greek, Uniate, and Orthodox church. Originally built as a wooden church in the early 17th century, the building gained its brick form thanks to funding from Tomasz Zamoyski, which took place between 1618 and 1631. An octagonal tower was built in the late Baroque style at that time, emphasizing its defensive functions in the context of the walls of the Zamość fortress. After the church was handed over to the Basilians in 1706, it became the site of a Uniate synod, and in the 18th century, it was surrounded by a monastery, which no longer exists. After the partitions of Poland, the building changed its denomination to Orthodox and received a new name, and many of its decorative elements were removed. After World War I, the church became the property of Roman Catholicism, but during World War II, it was handed over to the Greek Catholics. In 1945, the church came under the management of the Redemptorists, who restored its original dedication to St. Nicholas. The interior of the church is distinguished by valuable furnishings, including a late Renaissance portal, a Baroque holy water font made of black marble, and an original choir with a 16-voice organ. The church also has numerous decorations and stuccowork. The tower houses bells from the mid-20th century, which add a pleasant accent to the temple's architecture. The Church of St. Nicholas reflects the rich history of the city of Zamość and the changes related to its religious and cultural functions.