The complex structure of nationalism has given way to thinking that Islam and nationalism are mutually exclusive phenomena for a long time. This epistemological asymmetry is mainly based on the intellectual basis of nationalism, which originated from modern Western methodologies of social sciences, and its encounter with scientific methods of non-Western communities. However, a new dimension provided by the religious nationalism literature resulted in a reevaluation of nationalism and its epistemological asymmetry in different countries. This new dimension, which sees the possibility of a combination of nationalism and religion, was used in this study to understand the religious nationalism experience in the Late Ottoman Period through prominent intellectual and poet Mehmet Akif Ersoy’s essays in the famous Islamist magazine, Sebilü’r-reshad. In detail, this study analyses an under-explored aspect of the Islamist national poet, one of the most famous intellectuals of the late Ottoman period, and the author of the national anthem of modern Turkey: his understanding of religious nationalism. Then, the questions that need to be asked are “Did Mehmed Akif juxtapose Islam and Turkish nationalism? In other words, if so, how did he combine particularistic nationalism and universalist Islam? If there is a difference, how did Akif differentiate between nationalism and Islamism, and what kind of nationalism was he trying to avoid? How Akif reconstructed the concepts of Ummah, millet, country-vatan, and freedom-hurriyya, which all had meaning constructed throughout time and were influenced by religious norms. In other words, how these concepts were used differently from classical Islamic law and Qalam?” In order to answer these questions, I have benefited from two theories, which are “the theory of religious frontiers” and “the theory of multiplexity in Islam”, one is about nationalism and the other is about Islamic disciplines. The article argues that contrary to popular belief, Mehmet Akif Ersoy did not oppose nationalism but rather reinterpreted it in a way that supported it and harmonized it with the ontology, epistemology, and methodologies of Islam. In doing so, it will show to what extent the basic principles of nationalism are harmonized with Islamic law, theology, and Islamic ethics and how modern Turk-Islam synthesis was formed by Mehmet Akif.