The Ottoman-Turkish modernization, which is said to have started with the tenure of Selim the Third, connects Tanzimat (The Reorganizations), Abdülhamid the Second, the Constitutional and the Republican periods. Each of these periods definitely has unique characteristics of its own. Indeed, it is not so easy to differentiate the Tanzimat Era from the period of Abdülhamid the second in terms of internalization of a reformist strategy. In the same way, the Constitutional period represents a considerably significant horizon for the determination of the foundation philosophy of the new Turkish state through the reformist practices that were put forward in the name of maintaining the continuation of the state. It is also significant to emphasize the fact that Constitutional period is of special importance as one of the moments of the Ottoman-Turkish modernization. While analyzing political life in Turkey, there is a need to take into account the primary actors of the Constitutional period and the relationships between these actors. From the very first day that they emerged, the experiences of Young Turks put both the members of the Unionist Movement and the founding cadres of the Republic under its influence. The primary goal of this study is to analyze the relationships between the Unionists and Kemalists, especially Mustafa Kemal, by taking this influence as a central focus. It is possible to identify several common characteristics between the Unionists and Kemalists when compared in the light of social backgrounds, worldviews, relationships with each other and the political experiences they had gone through. It would not be wrong to claim that Kemalism has taken its place in history as a produce of the experiences of Ottoman-Turkish modernization, especially that of Unionists, without ignoring the differences between the two groups and without absolutizing these commonalities. Kemalism is Unionism melted with the conditions of the day and cast again.