The parish in Okonin was probably founded by the Teutonic Knights in 1325. The church was built in the middle XIV century. During the First Swedish War in 1626-1629, the church was destroyed. It was rebuilt around 1640 thanks to the foundation of Jan Działyński, the starost of Pokrzywno. The present call of St. Cosma and Damian only became established in the 17th century. During the works in 1841, the tower was raised, and in the years 1911-1913 a thorough renovation of the temple was carried out, adding a new sacristy and partly revealing the gothic polychrome. Subsequent conservation works were carried out at the temple in 1990-1996.
The church is a Gothic building erected of bricks on a stone pedestal. It has a aisleless, rectangular form without an externally separated presbytery. Quite unusually close to the north-east corner there is a massive, three-story tower. In its ground floor there is a former sacristy, and in the thickness of the walls there are stairs leading to the attic. Tower floors have been separated from each other by band friezes with plasters covered with painting decoration.
The interior of the church was originally covered with Gothic wall paintings. In the fourth quarter of the fourteenth century, the eastern, northern and southern walls were covered with them. At the beginning of the 15th century it were placed on the western wall.
The church has retained its Gothic shape and layout to this day, although its pointed-arched window openings were mostly enlarged in modern times, and the eastern and western gables were rebuilt in the 17th century.
Mroczko T., Architektura gotycka na ziemi chełmińskiej, Warszawa 1980.
Webpage odznaka.kuj-pom.bydgoszcz.pttk.pl, Kościół p.w. śś. Kosmy i Damiana w Okoninie.