The Sheikh Lotfollah Mosque (Persian: مسجد شیخ لطف الله, romanized: Masjed-e Shaykh Lotfollah;) is a Shi'ite mosque, located on the eastern side of Naqsh-e Jahan Square, Isfahan, Iran. Construction of the mosque started in 1011 AH (1602/1603 CE) and was finished in 1028 AH (1618/1619CE). It is one of the masterpieces of Iranian architecture from the Safavid era. It was designed by the chief architect Muhammad Reza during the reign of Shah Abbas the Great. On the advice of Arthur Upham Pope, Reza Shah Pahlavi had the mosque restored in the 1920s.
The Sheikh Lotfollah Mosque, completed in the Safavid style, is one of the most important architectural projects built on Isfahan's maidan, prominent for its location, scale, design, and ornamentation. The mosque is registered, along with the Naghsh-e Jahan Square and other surrounding structures, as a UNESCO World Heritage Site; and was added to the Iran National Heritage List on 6 January 1932, administered by the Cultural Heritage, Handicrafts and Tourism Organization of Iran.