Oscarskyrkan is a three-aisled hall church with two short, wide transepts to the north and south, and a straight-ended chancel to the east. The church's 80-meter-high tower, with a square base, is located in the southwest part of the building. Four smaller towers, housing staircases, complement the structure. The main entrance is on the west side, with the sacristy in an extension north of the chancel, and the so-called Silver Chamber to the south. The building's framework is made of brick.