This study aimed to assess the association of smartphone addiction with domains of the big five personality traits (i.e., extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience) after controlling for individual differences such as age, gender, and amount of daily smartphone and internet use. The study employed a cross-sectional survey design, with data gathered from 494 university students using the Turkish adaptation of the Big Five Inventory and Smartphone Addiction Scale. Hierarchical multiple linear regression analyses were applied in order to test two hypotheses. The study put forth that after controlling for the individual differences, the big five personality traits were found to significantly predict smartphone addiction. Agreeableness and conscientiousness were shown to be negative predictors, neuroticism was a positive predictor, and extraversion and openness to experience were not found to be significant predictors. The results of the study are discussed, and some implications are suggested, with revealing the relationship between personality traits and smartphone addiction aiming to help policymakers and practitioners in designing awareness raising activities in schools.