St. Johann, Parish church in Dillingen/Saar, Germany.

St. Johann is a rectangular hall church in Dillingen/Saar built in 1844–1845 in late Neoclassical round-arch style. Its light-ochre and reddish sandstone walls are articulated by blind arches framing the windows, and the west tower projects only by the thickness of the wall. The interior repeats the exterior wall system, giving the impression of an arcade zone in a single-nave church.

A church was first documented in 1150; the late Gothic building erected in 1450 by Johann von Dillingen was replaced in 1728–1732 by a larger church consecrated in 1732. The present church was built in 1844–1845 to plans by an unknown architect and consecrated on 9 November 1845 by Bishop Wilhelm Arnoldi. Pfarrer Philipp Schmitt contributed 1,000 of the 14,000 talers the building cost.

Locals call the church Alt Kirch, the mother church of Dillingen's inner-city parishes. It belongs to the parish community of Dillingen, one of five congregations, and is assigned to the Diocese of Trier. The patronal feast is the Nativity of John the Baptist on 24 June.

The church interior is open for visitors to explore and view its historical instruments and appointments. Those interested in hearing the organ should inquire about regular services or concerts that may be scheduled.

The architect of St. Johann is unknown: pastor Philipp Schmitt, who commissioned the 1844–1845 building, documented its construction carelessly. The change of patron from Saint Lucia to John the Baptist is also unexplained; it may relate to the nearby former hermitage on the Limberg, whose brothers followed the rule of the German Congregation of the Hermit Brothers of St. John the Baptist.