St. Kilian, Gothic Revival church in Iserlohn, Germany.

St. Kilian is a Gothic Revival hall church in Iserlohn-Letmathe, built of rough Westhofen sandstone blocks with a 73-metre northwest tower topped by a 19-metre spire. Its three naves lead to a four-bay nave with a suggested transept, and the choir is flanked by a two-storey sacristy.

Construction began in 1914 under architect Joseph Buchkremer and was delayed by World War I before the church was consecrated in November 1917. Its early years coincided with a period of major social upheaval in Germany.

Locals call St. Kilian "Kiliansdom" or "Lennedom", after the Lenne river by Letmathe. The parish keeps relics of Popes John Paul II and Pius X, the latter in the Herz-Jesu altar, and a relic of Kilian himself in a niche of the Kilians-Kapelle. In the baptistery a standing cross holds a nail of the third degree that touched the original crucifixion nail.

The main entrance is through the portal at the base of the 73-metre northwest tower, which leads directly into the four-bay nave. The interior is a three-nave hall church, so the side aisles run parallel to the central space and the choir lies at the far end, flanked by a two-storey sacristy. The organ galleries are on the side and centre upper levels.

St. Kilian holds a relic of Pope John Paul II in a cross-shaped reliquary on the Marian altar, and a relic of Pope Pius X in the Sacred Heart altar. A nail modelled on the one used at the Crucifixion, a third-degree relic, sits in a standing cross in the baptistery. The patron's relic is kept in a wall niche of the Kilian chapel.