The Holy Trinity Church, also known as Pyhän Kolminaisuuden kirkko, is an Orthodox temple of the Helsinki Metropolis of the Finnish Archdiocese of the Patriarchate of Constantinople. It is located in the Kruununhaka district, near Senate Square in Helsinki.

The church was built in the Empire style between 1825 and 1826, designed by Finnish architect Carl Ludwig Engel, and consecrated in 1827 in honor of the Holy Trinity. It is the oldest Orthodox church in the capital of Finland.

Since the early 19th century, after Finland joined the Russian Empire, the number of Orthodox parishioners in the country began to increase. The first Russian stone Trinity church in Helsinki was erected according to Carl Ludwig Engel's design in 1825-1826 in honor of the Holy Trinity. For this church, a one-tiered Empire-style iconostasis was made with funds from the Sinebrychoff merchants.

The Trinity Church has undergone several renovations; however, its interior has remained unchanged. Among the main relics of the temple are the icon of St. David of Thessalonica from the late 18th century and the icon of the Mother of God of All Sorrows, created in honor of the miraculous salvation of the imperial family during a train crash in Borki. Four Russian emperors visited the church: Nicholas I, Alexander II, Alexander III, and the future emperor Nicholas II. Today, it is the only Orthodox church in Finland where services are held regularly.