Hl. Dreifaltigkeit, Modern church in Fraulautern, Germany.

Heiligste Dreifaltigkeit is a Roman Catholic church built from 1949 to 1954 in Fraulautern, a district of Saarlouis. Its light beige and white interior has a wide, gently pitched ceiling of pale rectangular panels, round pendant lights and side aisles with rounded arches. A narrow red carpet runs between light wooden pews toward a rounded arched chancel with three tall stained-glass windows, blue-toned on the left and right and a central one with a crucifix mounted before it.

The present church was built from 1949 to 1954, after the ruins of its neo-Gothic predecessor, almost completely destroyed in the Second World War, were blown up. The parish traces its origin to a chapel founded by the nobleman Adalbert in memory of his son, confirmed in a document of Archbishop Hillin of Falmagne in 1154, around which an Augustinian monastery grew. In 2023 the church became the parish church of the new parish Heilige Familie.

The patronal feast is Trinity Sunday, the first Sunday after Pentecost. Since 2023 the church has been the mother church of the parish Heilige Familie, which unites the Catholics of Fraulautern, Roden and Steinrausch; the parish belongs to the Diocese of Trier.

The church stands in Fraulautern, a district of Saarlouis. The main entrance is at the end of the nave opposite the chancel; the red carpet marks the central aisle between the wooden pews. Side aisles run behind rounded arches on both sides.

The church keeps the patronal feast of the Holy Trinity on the first Sunday after Pentecost, and since 2023 it has served as the mother church of Fraulautern, Roden and Steinrausch. Its predecessor, a neo-Gothic building, was blown up before the present church was built between 1949 and 1954.