It is known through his memoirs, novels, stories and columns that the place of Istanbul in the life of Refik Halit Karay (1888-1965), one of the important artists of Turkish Literature, has always been different and important. Throughout his life, he witnessed important breaking points in the Ottoman Empire and the Republic of Türkiye. On the other hand, he has dealt with these processes in his twenty novels by touching on different aspects of Istanbul at different points. One of the most important topics that Karay’s novels deal with in general is the change in the understanding of Istanbulness, internal and external migration and Istanbulness. In this study, it is aimed to reveal how the new immigrants to the city are affected by the cultural-social life of Istanbul and how they affect the cultural-social life and places through the Istanbulness that Karay deals with in his novels. Refik Halit Karay generally depicted Muslim immigrants from different parts of Anatolia, the Balkans and partly from the Caucasus in his novels. In addition, he used the “White Russians”, the upper class of the nobles and soldiers of the tsarist regime who fled from the Soviet revolution and their families, from different angles in many of his novels, and dealt with their influence on the understanding of being an Istanbulite and the influence of Istanbulites on them.