The Dome of Soltaniyeh in Soltaniyeh city, Zanjan Province, Iran, traditionally so called, is a complex of ruins centering on the Mausoleum of the Mongol ruler Il-khan Öljeitü, also known as Muhammad Khodabandeh. The estimated 200 ton dome stands 49 meters tall from its base, and is currently undergoing extensive renovation. Other names the Dome of Soltaniyeh is known by are the Oljeitu Dome, Dome of Sultaniyya, the Tomb of Oljeitu and Gonbad-e-sultaniyeh.

Soltaniyeh, also Romanized as Solţānīyeh, Solţāneyyeh, Sultaniye, and Sultānīyeh; also known as Sa‘īdīyeh,) is a city in the Central District of Soltaniyeh County, Zanjan province, Iran, serving as capital of both the county and the district.