The Imamzadeh Hossein (also Emamzadeh-ye Hossein, Persian: مسجد جامع عتيق قزوین) is the grave mosque of Imamazadeh Husayn, son of the 8th Imam Ali al-Rida ("Hazrat-e Reza") in Qazvin, Iran that the Safavids - Shah Tahmasp I built in the mid-16th century as a pilgrimage center.

[1] The namesake of the tomb is the biennial deceased son of Imam Ali al-Rida.

This passed in transit with his father to Khorasan in Qazvin in 821 and was buried at the site.

The tomb is reminiscent of a generous palace complex with its own walled garden, plant rows, small Iwanen, niches, grave stones and precious blue and cream-colored tile decorations.

In this middle part carried by slender columns porch leads to areas segregated by sex and has two entrances; left for women, right for men.