Background: Few studies have investigated which factors were related to adolescents’ social media use. This study aimed to evaluate which factors were associated with heavy social media use on weekdays and weekends among 13-year-old adolescents.

Methods: We analyzed data from 3727 children from the Generation R Study, a population-based cohort study in the Netherlands. Associations of demographic factors (child age, sex, ethnic background, and family situation), socioeconomic position (parental educational level, parental employment status, and net household income), screen-based behaviors (computer playing and TV viewing), and the home environment (communication, supervision, and restriction) with adolescents’ heavy social media use (≥ 2 hours/day) were assessed separately on weekdays and weekends. Multivariate logistic regression analysis was applied.

Results: The prevalence of heavy social media use was 37.7% on a weekday and 59.6% on a weekend day. Being a girl, living in a one-parent family, and more time spent playing on the computer were associated with heavy social media use on weekdays and weekends (all P < 0.05). Low socioeconomic position adolescents (low parental educational level and low household income) were more likely to show heavy social media use only on weekends (all P < 0.05). Children whose social media use was restricted by parents on weekdays or children whose social media use was supervised by parents on weekends had lower odds of heavy social media use (all P < 0.05).