Lars Eliel Sonck was born on 10 August 1870 in Kälviä, Central Ostrobothnia. Sonck’s parents were vicar Knut Sonck and Anna Rebecka Nordström.

Sonck took his matriculation examination from the Turku Swedish General Lyceum in 1888 and after that studied at the Technical School of Turku. In 1890 he started to study architecture at the Polytechnical Institute of Helsinki. As a student, he took part in art historical expeditions, arranged the Finnish Antiquarian Society, to Western Uusimaa region, Satakunta region and Tavastia region. Sonck also made study trips to Scandinavian countries, Germany, Austria and France. Sonck won the architecture competition of St. Michaels Church in Turku in 1894, the same yeard he received his diploma of architecture.

The other important work in Sonck’s career was the Tampere Cathedral, based on an architecture competition in 1899 and completed in 1907. Sonck also designed Kallio Church in Helsinki, completed in 1912. Sonck became known as one of the most famous Art Nouveau architects in Finland. Apart from the churches, some of his most well-known works area Eira Hospital in Helsinki, and Kultaranta, the summer residence of the president of Finland in Naantali, Western Finland. He also designed buildings to Mariehamn, Åland. The Mikael Agricola’s Church in Helsinki, completed in 1935 was Sonck’s last major design project.

Lars Sonck died at the age of 86, on 14 March 1956 in Helsinki.