Islamic architecture, as one of the most significant manifestations of Islamic civilization, has been shaped over centuries by a variety of cultural, social, and religious transformations. Among these, the architecture of mosques during the Safavid period holds a prominent place due to its coincidence with the official establishment of Shi’ism in Iran. The Safavids, by declaring Shi’a Islam as the state religion, played a vital role in transforming and developing mosque architecture. This study aims to examine the profound impact of Shi’a beliefs on religious architecture in Safavid Iran. These influences are particularly evident in architectural elements such as domes, minarets, mihrabs, and inscriptions. Through a descriptive-analytical approach and based on library resources and previous research, the study investigates the role of Shi’ism in shaping religious architecture. Special attention is given to distinctive Shi’a architectural features such as double-shelled domes, Quranic and hadith-based tile decorations, and the symbolic use of the number 12 representing the Twelve Imams of Shi’a Islam. The findings reveal that Safavid mosques functioned not only as places of worship but also as political and religious symbols of Shi’a Islam. Their precise and artistic decorations reflect the power and grandeur of Shi’ism and the Safavid state, playing a crucial role in the formation of religious and political identity during the period. This research contributes to the existing knowledge of Islamic religious architecture, particularly from a Shi’a perspective, by highlighting the religious, artistic, and cultural impact of Shi’ism on Safavid mosque structures.