Holy Trinity cathedral in Kansk, Regional cultural heritage cathedral in Kansk, Russia.

Holy Trinity Cathedral in Kansk is a stone church built in the late Siberian Baroque style, with a tall central cube crowned by five decorative cupolas. Lower single-domed side chapels flank it to the north and south, while a refectory and a tall octagonal bell tower stand to the west. It is the oldest stone building in the city.

On 21 September 1797 Archbishop Varlaam of Tobolsk authorised a stone church for Kansk's parishioners, replacing the wooden Saviour church. Work began on 18 May 1800 under Yenisei masters Alexei Kazaretin and Andrei Maletin; the warm side chapel was consecrated on 22 January 1805 and the cold church on 5 June 1814. The building was enlarged in the 1840s and rebuilt in 1912–1913, when the refectory vaults were raised.

The main altar, originally dedicated to the Saviour, was consecrated to the Holy Trinity after the building was returned to the church in 1992. Since 2011 the cathedral has housed the bishop's seat of the Kansk eparchy. It keeps icons with relics, among them Saint John the Baptist, Nicholas the Wonderworker and Matrona of Moscow.

The cathedral is open to visitors, though it is an active place of worship where services are held regularly. Plan your visit outside of prayer times for a quieter experience, and wear respectful clothing when entering.

The cathedral holds six icons with relics, among them a particle of the coffin of Blessed Matrona of Moscow and relics of St. Ignatius (Brianchaninov). The main altar, originally dedicated to the Saviour, was reconsecrated to the Holy Trinity after the building was returned to the church in 1992.