Holy Trinity Orthodox church in Slonim, Eastern Orthodox church building in Slonim, Belarus.

The Holy Trinity Orthodox Church in Slonim is a brick structure with distinctive architectural features, including an octagonal tower with buttresses and two cubic extensions. Gray helmet domes sit atop the structure, shaping its exterior and setting it apart from other churches in the city.

A wooden church founded in 1630 by Andrzej and Katarzyna Radwan was replaced by the brick Bernardine church built in 1639–1645 and consecrated in 1671. The monastery's residential wing followed in 1749. In 1866 the church was converted into the Orthodox Holy Trinity Church by provincial engineer V. F. Nebolsin and consecrated in 1867.

The church keeps its Bernardine past in its fittings: the 18th-century main altar of dark-brown stucco, set into the apse wall, carries figures of angels, and an iconostasis was installed after 1864. The icon of the Holy Trinity (18th century, oil on canvas) hangs in a rectangular frame at the centre of the altar's first tier. The ornament follows Rococo themes — pilasters, volutes, rocaille, shells and vases.

The church stands at 23 Vasi Kraynego Street, in the eastern part of Slonim's historic core on the left bank of the Shchara. The former Bernardine monastery adjoining the apse now houses a dormitory of the Slonim State Medical College. The complex is listed as a republican-level historical and cultural value of Belarus.

Small openings in the arched niches around the bell tower are relics from its time as a fortress structure. These loopholes reveal that the church was designed not only for worship but also to help defend the city.