The Chahar Suq and Hajj Muhammad Husayn Mosque (; ), is a Shi'ite mosque located opposite the Ardakan Seminary, in the center of the city of Ardakan, in the province of Yazd, Iran.
Completed in 1834 CE, during the Qajar era, the mosque was added to the Iran National Heritage List on 20 January 1975, administered by the Cultural Heritage, Handicrafts and Tourism Organization of Iran.