The Rmanj Monastery (Serbian Cyrillic: Манастир Рмањ) is a Serbian Orthodox monastery located in Martin Brod, north-western Bosnia and Herzegovina, at the left bank of the Unac River, near its confluence with the Una River. The patron saint of the monastery is Saint Nicholas. It was probably founded in the late 15th or early 16th century. After the Ottoman Empire's conquest of the area, the monastery was temporarily abandoned in 1578. In the early 17th century, it became the see of the Serbian Orthodox Metropolitanate of Dabar-Bosnia, and it remained in this capacity for about 110 years. After the monastery was burned down by the Turks in 1663, it was later rebuilt and reoccupied in 1737. It was burned down again during the Austro-Turkish War of 1787–1791. Ottoman authorities allowed the renovation of the monastery in 1863, and it was rebuilt in two years. It was badly damaged during the anti-Ottoman uprising in Bosnia in 1875 and 1876. Next year, Arthur Evans visited Rmanj (spelled as "Ermanja" by him), and he described in a letter the damage inflicted on the monastery's church by troops under a Bosnian Muslim feudal lord. Once more, the monastery was repaired in 1883.
In World War II, a field hospital of the Yugoslav Partisans was organised at the monastery. For this reason, it was bombed by the Germans and completely destroyed on 23 April 1944. In 1974, authorities of the Socialist Yugoslavia allowed the renovation of the monastery. Its church was completed in the 1980s, and the foundation of the monks' dormitory was consecrated in 1993. In 1995, during the Croatian Army's Operation Storm, the monastery was shelled and badly damaged. Afterwards, Croatian soldiers mined the monastery's church, but the mines were removed by British soldiers of the SFOR. The dormitory was completed in 2006, and in the following year, the monastery was inhabited by three monks. In 2007, the Rmanj Monastery was proclaimed a National Monument of Bosnia and Herzegovina.
- Ljiljana Ševo (2007). "Serbian Orthodox monastery of Rmanj". Bosnia and Herzegovina Commission to Preserve National Monuments.
- Arthur Evans (1878). Illyrian Letters. London: Longmans, Green, and Co. pp. 38–39.
- Radovan Pilipović (2007). "Манастир Рмањ у прошлости и садашњости" (in Serbian). Pravoslavlje.