Designed by Carl Ludvig Engel in 1843, the magnificent St John's Church is the third church to be built on Hamina's Town Hall Square. The two previous ones, Ulrika Eleonora's (1742) and Elizabeth's (1821), were destroyed by fire. The present church is built of brick in empire style and rectangular in shape.

St. John's Church did not rise on the ruins of its predecessors, but Ulrika Eleonora's Church and Elizabeth's Church were located on the opposite side of Town Hall Square, on the site of the present Orthodox Church. The location of St John's Church is very significant in Finnish history, as it was the site of the former commander's house where the Peace of Hamina was signed in 1809. In the Peace of Hamina, Sweden ceded the whole of Finland to Russia.