English: Helsinki Cathedral is an Evangelical Lutheran cathedral of the Diocese of Helsinki, located in the centre of Helsinki, Finland. The church was originally built as a tribute to the Grand Duke, Nicholas I, the Tsar of Russia and until the independence of Finland in 1917, it was called St. Nicholas' Church.

After a fire destroyed most of Helsinki during Russian rule, the new city square was inaugurated as part of the 19th-century reconstruction. The Tuomiokirkko was built to replace a smaller 1727 church but when the designer Engel died in 1840 and work was taken over by Ernst Lohrmann who added the zinc statues of the twelve apostles on the roof, a bell tower, and a side chapel to Engel's design. The church was completed in 1852 and took 22 years to complete.

The inside of the Cathedral is plan as are most Lutheran churches and has a seating capacity of 1,300.