Þjóðveldisbærinn Stöng (Icelandic: [ˈθjouðˌvɛltɪsˌpaiːrɪn ˈstœyŋk], Stöng Commonwealth Farm) is a reconstructed viking-era farmstead in Iceland, located in the Þjórsárdalur valley near road 32 in Árnessýsla county. It is a historically accurate reconstruction of the three buildings, including a longhouse, which stood 7 km to the north at Stöng; the farm is believed to have been buried under volcanic ash in 1104 following the eruption of the volcano Hekla.

The reconstruction was built in 1974 as a part of the national celebrations of the 1100th anniversary of the settlement of Iceland in 874.