Garnisonkirche Oldenburg, Gothic Revival church in Oldenburg, Germany.

Garnisonkirche Oldenburg is a Protestant brick church in Gothic Revival style featuring pointed arches and tall windows that define its interior space. The central tower displays intricate stone carvings and geometric patterns that distinguish the building from afar.

Built from 1901 to 1903 to plans by Jürgen Kröger and consecrated on 18 October 1903, the church served the Prussian Oldenburgisches Infanterieregiment Nr. 91 and Dragoner-Regiment Nr. 19. After World War I the military congregation shrank, and on 13 February 1921 it opened for the Ev.-Luth. Kirchengemeinde Oldenburg. From 1937 a full-time military chaplain returned; Martin Niemöller spoke here on 21 October 1936. The congregation bought the building from the Federal Republic on 15 January 1987.

The name refers to the garrison congregation: the church served the Prussian Oldenburgisches Infanterieregiment Nr. 91 and Dragoner-Regiment Nr. 19. Since 30 November 2014, when Bishop Jan Janssen and church president Martin Heimbucher held the first Reformed service here, the church has also hosted Oldenburg's roughly 4,500 Reformed members, with a Reformed service on the first Sunday of each month and on high feast days.

The church stands at the northern end of Peterstraße. Reformed services are held on the first Sunday of each month and on high church holidays, alongside the Lutheran Sunday services; visitors should check the parish's current times before coming.

The 1965 organ by Alfred Führer of Wilhelmshaven has 35 stops on three manuals and a pedal, with mechanical key and stop action. The five Rincker bells differ in size: the oldest, cast in 1901, measures 73 cm across, while later bells of 1959, 1961 and 1982 reach 93, 104, 67 and 60 cm.