The dedication Mass will be celebrated by Cardinal Nicholas Cheong Jin-suk, Archbishop emeritus of Seoul, on 25 June, the date when war broke out in 1950.
According to the Korean bishops' conference, the Penitence and Atonement Church and National Reconciliation Centre is intended as a symbol of inter-Korean reconciliation, peace and reunification.
Located in Paju, north-west of Seoul, the project was begun by a group of North Korean Catholic defectors who purchased a plot of land in 1997.
The Archdiocese of Seoul later took over the initiative and building started in 2006.
The church is modelled on two Catholic churches that existed in North Korea before the war, the Seoul-based Yonhap News Agency reported.