Oscarskyrkan was designed by the architect Gustaf Hermansson, who won a public competition for the commission despite a lukewarm reception from Stockholm's press at the time, who felt the entries followed a formulaic German Gothic model. The church takes its name from King Oscar II, marking his 25th jubilee as monarch; he laid the foundation stone in 1897, though construction was delayed by problems with the foundations, late deliveries and strikes, so the building was not consecrated until 1903. It is built of roughly hewn pale grey limestone in a three-aisled hall-church plan with short transepts and a squared-off chancel in the English manner, its nave vaults carried on ribbed pointed arches above reddish granite columns.
While the exterior has changed little since 1903, the interior has been substantially reworked. A first restoration in 1921–22, led by Lars Israel Wahlman, replaced the original plain-glazed windows and introduced the church's principal attraction: 33 stained-glass windows by the Norwegian artist Emanuel Vigeland, completed over three years and installed by 1929. Drawing on medieval French glasswork, particularly that of Chartres, Vigeland's windows explore the relationship between the Old and New Testaments. A later restoration in 1954–56, led by Otar Hökerberg, removed vault paintings and replaced Hermansson's original neo-Gothic altarpiece with a new gilded-bronze altar designed by John Lundqvist, depicting themes of life and death around a central figure of Christ.