Ørje Fortress lies in Marker municipality in Østfold county, Norway. The fortification was built in 1902 and 1903 to guard the heavily trafficked route through Ørje, which was an important entry point from Sweden.
The fortifications consist of two parts: the northern fort and southern fort. The northern fort lay southwest from Ørje bridge and sluice: the southern fort was at Likollen, 1 km further south.
Both were positioned on elevated positions and were armed with four canons. Each of the forts had two 105 mm guns and two 75 mm rapid fire fortification guns.
According to the Karlstad Treaty, the forts were taken out of service and demolished in 1905. The guns were dismounted and relocated to Hegra Fortress.
The northern fort was restored in 1991.