The Republic of Turkey and Syria have many similarities and differences due to their common history and being within the geopolitical framework of the Ottoman Empire. Syria was the only country that separated from the Ottoman Empire and had long-standing territorial and border problems with the successor of the empire, the Republic of Turkey, which brought the two countries to the brink of war many times. Relations between Turkey and Syria have always been tense since the country's independence from France in 1945, except for a limited period at the beginning of the 21st century. Issues such as: territorial disputes over Hatay province, border rivers between the two countries, the Kurdish issue, Turkey's proximity to the United States and, on the other hand, Syria's proximity to the Soviet Union were among the most important reasons for the deterioration of relations between the two countries. Although Turkey’s role in the civil war and its interference in Syrian affairs have been widely discussed in Iranian academic circles due to Turkey’s involvement in Syria and the conflict between its interests and those of Iran, less attention has been paid to the fact that the history of the conflict between Turkey and Syria dates back decades before the start of the civil war and to the mid-twentieth century. The following descriptive-analytical study attempts to examine the history of Turkey-Syria relations by using a library method and various books and articles in the fields of international relations, history, and political geography, and to explain various aspects of this issue.