The purpose of this study is to examine the smartphone addiction levels among university students. For this purpose, first of all, students' addiction levels were determined, and then it was examined whether these levels differed according to the gender of the students, the purpose of using the internet on the smartphone, and the usage times of smartphones. The causal comparison method was used in the research as a quantitative research method and the sampling of the research consisted of 435 students studying in the Faculty of Theology at Ondokuz Mayis University and who were determined by the accessible sampling method. In order to determine the smartphone addiction levels of university students, the data was obtained with the Smartphone Addiction Scale. Descriptive statistics, the independent samples t-test, and one-way analysis of variance were used to analyze the obtained data. The results of the research showed that students studying in the Faculty of Theology had low levels of smartphone addiction, male students had higher levels of smartphone addiction compared to female students, the use of social media via smartphones increased the risk of addiction, and that students with a higher average daily smartphone usage also had higher levels of addiction.