Al-Rashid Mausoleum (Persian: آرامگاه الراشدبالله) or Imamzadeh Husayn (امامزاده حسین)is a historical mausoleum in Isfahan, Iran. It dates back to the Seljukid era and is located on the northern bank of Zayanderud beside the Shahrestan bridge.

This structure was originally a 12th-century mosque, which was built on the ruins of a Zoroastrian fire temple which was destroyed during the Rashidun conquest of Iran in the 7th century. It was also said that the mosque was built over a temple for Mithraism. The Abbasid caliph of Baghdad, Al-Rashid Billah, fled to Isfahan after having conflict with the Seljuk Sultan Mahmud II, but was subsequently assassinated and buried in the northern corner of the mosque, which was developed into his tomb. However, the mosque and its minaret were demolished several centuries later, and only the structure of the tomb remained with its single dome.

At some point of time, a personality named Husayn ibn Zayd al-Hasani was buried in the mausoleum, and it was given the name Imamzadeh Husayn due to this. A wooden zarih was built around the grave of Husayn. Later, another person named Shah Ibrahim was buried in the building.

• List of the historical structures in the Isfahan province