Saint Catherine of Siena church in Třešť, Catholic church in Třešť, Czech Republic.

Saint Catherine of Siena Church, locally called the "lower church", stands in the centre of Třešť, unlike the "upper" Church of St Martin by the château. It is a Gothic-Renaissance building with a flat-ceilinged nave and a tower in the western façade; the presbytery and adjoining sacristy were added in 1606, and a Renaissance porch stands on the south side. A stone column shrine from 1701 stands before the south entrance.

Founded probably in 1492 by the Vencelík family as a German Lutheran church, it was first documented in the 16th century. The presbytery was added in 1606 and the church was restored in 1660 after the Thirty Years' War. A fire during the great blaze of Třešť on 1 October 1824 destroyed the interior, organ, roof and tower bells; restoration followed in 1842.

Locals call it the "lower church" to distinguish it from St Martin's by the château. It was founded by the Vencelík family as a German Lutheran church, and the red-marble late Renaissance tomb of Jan Václav Vencelík, who died on 9 February 1606, stands inside.

The church is accessible in the center of Třešť and welcomes visitors during scheduled service times. It is advisable to check opening hours or attend during services to ensure access to the interior.

On the outer wall hangs the tombstone of an unknown knight bearing half a crowned lion; its date and owner are unknown, perhaps a member of the Lipovický family. Inside, a red-marble late Renaissance slab from 1606 depicts Jan Václav Vencelík of Žirovnice in armour, holding a sword and a plumed helmet above the Vencelík coat of arms.