St. Marien, Catholic church building in Delmenhorst, Germany

St. Marien is a red-brick neo-Gothic hall church in Delmenhorst, built 1901–1903 to a design by Heinrich Flügel and rebuilt by 1949 after wartime destruction. A three-bay nave links the western tower to the transept, followed by a recessed choir closed by a polygonal apse and flanked by side apses. The tower's top storey holds the bell chamber behind biforia, and the spire is a solid cone ringed by four small pointed spires.

The building was constructed between 1901 and 1903 based on designs by architect Heinrich Flügel. Following substantial destruction during the Second World War, it underwent reconstruction that lasted until 1949.

The parish belongs to the Delmenhorst deanery within the Bishopric of Münster's Offizialat, and its parish office is at Louisenstraße 30. The community runs a Kita and family centre, a library, youth and women's groups and several choirs. The fourteen Stations of the Cross are cast iron reliefs on the side walls and rear wall.

The parish office is at Louisenstraße 30, not in the church itself. The church stands in central Delmenhorst, close to the coordinates 53.05133, 8.62704. The parish's two cemeteries lie elsewhere: the old Catholic cemetery on Schanzenstraße dates from around 1905, the new one on Oldenburger Landstraße from the early 1930s.

The western gallery houses a 47-register organ crafted by builder Alfred Führer in 1961, which continues to fill the church with music. The tower contains six bells, including the Marienglocke cast by the Otto foundry.