This study investigates the relationship between social media use, Big Five personality traits, and subjective well-being to determine how different personality traits relate to different measures of social media use and well- being, and which variable influences well-being the most. Participants completed established measures for the Big Five personality traits, social media engagement, social media intensity, satisfaction with life, positive and negative affect, and depression. Results showed that extraversion predicted social media engagement and intensity, and social media time. Conscientiousness predicted spending less time on social media. In addition, conscientiousness, extraversion, agreeableness, and neuroticism predicted positive well-being stronger than did social media use. When conducting five separate regression analyses with a social media use variable and a different personality variable each time, four times (conscientiousness, extraversion, agreeableness, and neuroticism) the personality variable predicted negative well-being more strongly than did the social media use variable. However, negative well-being was predicted more strongly by social media use than by the fifth personality variable, openness to change. Results are discussed and possible future investigations are suggested.