The Mausoleum of Prophet Qeydar (Farsi: آرامگاه قیدار نبی) is a historic mausoleum located in the city of Qeydar in Khodabandeh County, Iran. It is believed by locals to be the burial place of Qedar, the son of Ishmael. The mausoleum is number 321 on Iran's list of national heritage monuments.

The original structure existed before the 14th century but was badly ruined. The present structure was built in 1319 under the orders of Bulughan Khatun, the wife of the Ilkhanid ruler Ghazan. In 1350, the building was restored and renovated with funding from a Sufi religious leader named Timur Khan Soltaniyeh. In modern times, between 1901–1902, the governor of Zanjan, Jahanshah Khan, restored the mausoleum.

The mausoleum was eventually registered as a national heritage monument of Iran, with the number 321 in the current list.

The mausoleum of Prophet Qeydar has an area of approximately 120.40 square metres, in a rectangular shape, its central chamber topped by a brick dome. The entrance is on the southern facade. On the southern side of the shabestan is an early Nastaliq inscription dating back to 1319, which details the construction of the new building by Bulughan Khatun.

Walnut wood embedded with gold and silver is used to construct the zarih that encloses the grave of Qedar in the central chamber of the mausoleum. Islamic calligraphy can be seen engraved in the tomb chamber as well. Aside from housing a tomb and prayer hall, the building includes a hostel for pilgrims as well as a basement that was used to rear cattle. There are rooms for the clerics to hold meetings.

The mausoleum is believed to entomb the remains of Qedar ben Ishmael, who was one of the sons of Ishmael and the progenitor of the Qedarites in biblical tradition. In Islamic tradition, which accepts the biblical narrative, adds on that Qedar is an ancestor of the prophet Muhammad, hence the importance of this tomb. A historical copy of the Qur'an is also stored within the building; it is written on papyrus before being binded with a leather cover.

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  One of the arched gateways when viewed from the inside
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  A swimming pool in the foreground of the mausoleum.
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  Nastaliq inscription in the mausoleum.
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  The tomb of Qedar within the central chamber of the building.
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  Decor and carvings underneath the central dome; the top of the zarih is visible.

• List of burial places of Abrahamic figures
• List of mausoleums in Iran