In the second half of the 19th century, Tehran witnessed profound physical, social, and spatial transformations in the context of the expansion of Iran's political relations with European powers, including Britain. One of the less studied consequences of these developments is the redefinition of the pattern of establishment of religious spaces of religious minorities in the capital. Focusing on the role of diplomatic spaces, especially the British Embassy, ​​the present study attempts to show how these institutions played a role beyond their official function in producing new patterns of security, neighborhood, and urban visibility for Jewish, Christian, and Zoroastrian minorities. The theoretical framework of the present study is based on Henri Lefebvre's theory of the "social production of space," which considers space as a product of power relations, social actions, and symbolic mechanisms. The research method is analytical-descriptive and is based on historical documents, travelogues, maps of Tehran during the Qajar period, and spatial analysis of case studies. The findings show that the proximity to diplomatic spaces, especially in the area of ​​the Government neighborhood and axes such as Sī-e Tīr Street, enabled the formation of a kind of "quasi-safe territory" that encouraged minorities to gradually leave traditional closed neighborhoods and settle in new urban contexts. The study of the Jeanne d'Arc Church, St. Peter Church, Haim Synagogue, and Adorian Fire Temple shows that these spaces were directly or indirectly affected by the presence of diplomatic institutions at three levels of imaginary, tangible, and lived space. The results of this research show that diplomacy and international relations played an active role in shaping the religious geography of late Qajar Tehran, and understanding it is essential for rereading the spatial and social history of the capital.