Cathedral St. Marien Fürstenwalde, Gothic cathedral in Fürstenwalde/Spree, Germany.

St. Mary's Cathedral is a three-aisled brick Gothic church with a steep tiled roof, a polygonal apse, and a 68-metre white-plastered west tower topped by a dark dome and clock. Unhewn fieldstones from the earlier church are visible in the apse and side walls. Inside, a flat wooden ceiling replaces the destroyed vaults, and steel-framed glass walls separate rooms under the organ gallery from the nave.

The church became the seat of the bishops of Lebus in 1373, confirmed by papal bull in 1385, and served as their cathedral until 1558. Hussites destroyed it in 1432, and a new cathedral was begun in 1446. The first Protestant service was held on 12 April 1557. Air raids and artillery in April 1945 wrecked roof, tower and interior; rebuilding lasted into the 1970s and the exterior was finished in 1995.

The name St. Marien refers to Mary, to whom the church was dedicated as cathedral of the Lebus diocese. Since 1557 it has been Protestant: the first Protestant service was held on 12 April 1557 in the presence of Elector Joachim II. Today the parish centre sits inside the church, separated from the nave by steel-framed glass walls.

The cathedral is located near the town center and is easily reached on foot from the main streets. Visitors should note that the building serves as an active place of worship, so visiting hours may vary depending on religious services and events.

The organ now in the cathedral was built in 1967 by Alexander Schuke for St. Thomas Church in Leipzig, where Johann Sebastian Bach had worked. It was moved to Fürstenwalde, rebuilt and enlarged to four manuals and 64 stops, and installed in 2005. The cathedral hosts an international recital series.