St. Michael Church in Turku is based on an architecture competition arranged in 1894. The first prize was awarded to young architecture student Lars Sonck on his Neo-Gothic entry ‘Soli Deo Gloria’. The project was delayed due to financial difficulties. Sonck had moved towards Art Nouveau style and wanted to change his earlier Neo-Gothic plans. The parish was rejected first the development of the plans but Sonck managed to change some parts of the plan towards Art Nouveau style. The church can be seen as an eclectic mix of Neo-Gothic and Art Nouveau styles.

The castle-like Art Nouveau church was built in 1899–1905 on a steep hill in the middle of the low-rise wooden city. One of its focal features is the monumental stairs leading from the street to the main entrance on the eastern façade. Sonck used this theme in many public buildings throughout his career. Sonck’s father Knut Sonck was the vicar of Finström parish in Åland and church architecture became younger Sonck’s lifelong interest.

St. Michael Church main façade material is red brick. The bell tower that is the highest of three towers, is situated on the eastern façade. The chancel in the western end of the building is marked in the elevation with two towers. The interior is dominated by impressive Art Nouveau ornaments.

Architect Max Frelander assisted Sonck in the interior decoration plans. Master decorator S.Koskinen was in charge of the implementation of the decoration plans. Painter Willy Baer was in charge of the pinewood themed paintings in the chancel windows that were destroyed during the air raids of the Winter War. Artist couple Hilkka Toivola and Otso Karpakka painted new Gothic style paintings to the chancel windows in 1953.