Today's Iranian geography is an extremely important geography in terms of Turcology studies. This geography, which has a deep history and civilization, is a rich treasure waiting to be discovered both with its historical background and as of today. In order to discover and understand this treasure, many disciplines seek answers to important questions from their own point of view in Iranian Turcology studies and share the data they have obtained with the scientific world in a way that different disciplines can use. In this context, one of the important questions of Iranian Turcology studies is "What is the Turkish population in today's Iran?" is the question. This article will focus on both population and ethnic data of Hamadan province, although not all of Iran. In this sense, the framework of our study is the study titled "History of Political Divisions of Hamadan Province" published by Ahmad Heydari in 2020. The data on ethnic groups in Heydari's study were determined by us and answers were sought to the questions of which ethnic groups, especially Turks, live in the province of Hamadan today and what is their population. In the article, the necessary information is presented in a row, starting from Iran, where the deductive method was applied, to the province of Hamadan. While presenting the population and ethnic data of Hamadan province, the inductive method was applied and the data were arranged in a row to cover the entire province, starting from the villages. Finally, quantitative data consisting of numbers were subjected to a qualitative analysis and concrete outputs were obtained regarding all ethnic groups, especially Turks, in Hamadan province.