Schmerzhafte Mutter St. Maria-Kirche, Catholic church in central Flensburg, Germany.

St. Marien Schmerzhafte Mutter is a neo-Gothic brick hall church built 1898–1900 to plans by Heinrich Flügel, set on a slope above Flensburg's old town beside Burg Schöneck. Its polygonal choir faces north, the tower with the main portal and a large rose window stands at the southwest, and inside is a ribbed vault. The tower kept only a flat roof until the spire was finished in 1909.

Construction of the church began in 1898 under builder E. Breitschneider, but faced significant obstacles due to marshy soil conditions. The building was finally consecrated in January 1900 after these structural challenges were overcome.

The parish was founded after the 1864 war, and its first priest was Rudolf Rave. The church's name, Schmerzhafte Mutter, refers to Mary as the Sorrowful Mother. In 2014 the parish marked its 150th anniversary with ecumenical celebrations. The church also serves a large parish of about 12,000 members extending to Kappeln.

The church stands at Nordergraben 36 and Heiligengeistgang 16/18 on the western slope above the city centre, beside Burg Schöneck. A bus stop named "Katholische Kirche" is directly in front of it. The main portal is on the south side of the tower, and the Josefskapelle is reached through the courtyard entrance.

The tower holds three bronze bells tuned to f', g' and b'. The apse, built on soft peat and sand, began to slip and was stabilised on a new foundation in 1980/81, after which the vault damage was repaired. The church also has a small St Joseph's Chapel reached from the courtyard entrance.