The church was built around 1355 on the site of an older wooden temple. It was founded by king Casimir the Great. The popular but untrue theory is that the king raised the temple as a redress for the death of the canon Marcin Baryczka drowned in the Vistula River on the royal order for too boldly appealing the monarch in relation with his dissolute lifestyle.
At the turn of the 16th and 17th centuries the church was enlarged by the addition of the northern chapel and the porch of the west. In 1630 it was destroyed during a city fire. The period of Swedish wars, during which Szydłów suffered again, was not conducive to reconstruction. Probably for many years the church stood not covered by a roof, which contributed to the collapse of burned and overburdened vaults. It survived only the vault above the sacristy and the northern chapel, thanks to they small span and significant thickness. The restoration of the church continued with the intervals until 1671. The last stage of the expansion of the church was the addition of a styleless porch to the south portal in 1872.
In 1944, the parish church suffered a great deal of damage as a result of arson, but paradoxically, it contributed to the restoration of its original appearance, because it made easier to understand the original layout and appearance of the church, obliterated by later reconstruction.
The church is an orientated building, built in Gothic style, originally two-aisle and hall type on a rectangular plan with a polygonal ended chancel. From the north, a Gothic sacristy with a cross-rib vault was attached to it. The church was built of bricks, which makes it exceptional among the remaining Szydłów monuments. Stone was used to make bases, cornices and window frames. On the western side there is a richly moulded, pointed portal from the 14th century. A similar ogival Gothic portal is located on the south side. The whole structure is reinforced by numerous buttresses, between which there are ogival windows, in the sacristy crowned with trefoils. Near the church is the belfry adjacent to the town walls.
Website szydlow.kielce.opoka.org.pl, Historia Parafii.