Church of St. Sigismund was established in 1401 as a wooden object. At the end of the 15th century, the Cracow burgrave and the supremus thesaurarius Jakub Szydłowiecki began to build a brick temple. The work was completed by his brother Mikołaj Szydłowiecki, the Radom castellan and the supremus thesaurarius, around 1525. He also raised from the south a chapel that was the necropolis of the family, in which the ashes of his own, his father Stanisław and his brother Jacob rested. For the decoration of the church and the chapel, he most likely brought the famous Stanisław Samostrzelnik from the Mogiła. In 1563 the church was closed by Mikołaj Radziwiłł the Black, a fierce Calvinist. Catholics restored it perhaps in 1567, Mikołaj Krzysztof Radziwiłł the Orphan.
The church is built of local sandstone, orientated. It consists of a three-span chancel and a rectangular, wider and higher nave. From the north to the chancel lies a two-span, gothic sacristy and a single-span treasury. In turn, to the nave from the south adjoins the chapel of the Blessed Virgin Mary, while from the north the chapel of St. Stanislaus and the porch. Also on the axis of the church, from the west, to the nave adjoins the porch dating back of the redevelopment of Radziwiłłów family. The walls of the church are covered with steep buttresses, and the church is surrounded by profiled cornices. Brick gables of the nave include arcade blendes and stone shields with the coat of arms of Mikołaj Szydłowiecki.
Inside the chancel is stellar vaulted and the nave has a ceiling. Some of the preserved polychromies in the main nave, as well as on the primal ceiling of the nave, is probably brought from the Mogiła, Stanisław Samostrzelnik. Specific exterior decoration of the outer walls of the church on the south side are inscriptions engraved in sandstone blocks. They contain drawings, names, surnames and dates indicating that they were created at the turn of the 16th and 17th centuries. Probably they were a form of commemoration of the inhabitants of the town resting on the church cemetery. Next to the church in the cemetery stands a 16th century belfry.
Krasnowolski B., Leksykon zabytków architektury Małopolski, Warszawa 2013.
Website wikipedia.org, Kościół św. Zygmunta w Szydłowcu.