St.-Nikolai-Kirche, Gothic church in Osterburg, Germany.

St.-Nikolai-Kirche is a church with three naves and an irregular three-apsid choir built from field stones and bricks. A rectangular tower rises above the structure, topped by a baroque dome that was rebuilt following a city fire.

The core of the Gothic brick church probably dates to the second half of the 12th century, when a cross-shaped fieldstone basilica with a rectangular tower stood here. In the mid-13th century it was rebuilt as a three-aisled hall church, keeping the 13th-century supports. Around 1484 a three-aisled choir with three irregular apses was added, and in the same year the All Saints' Chapel was founded on the north side, now the sacristy. Damaged in the Thirty Years' War and again by a town fire in 1761, the church lost its Gothic spire and much of its furnishings.

The wooden pulpit was carved in the second half of the 16th century and first stood in the Marienkirche in Salzwedel before being moved here. The bronze font, decorated with vine scrolls and stylised lilies, carries an inscription naming the Münster master Volker and the year 1442. Above the altar hangs a large wooden crucifix made in the mid-15th century, brought from the Altmärkisches Museum in Stendal.

The church is located on Kirchstraße in Osterburg and is straightforward to reach. Visitors should be aware that regular services and events may occasionally limit access to the interior.

The 1890 altar cross by woodcarver Gustav Kuntzsch of Wernigerode, donated by royal building officer Georg Ludwig Gerlhoff, was removed during the 1953-1957 restoration and now sits unrestored in a storage room of the church.