Based on tenth-grade students' perceived ICT (information and communication technology) competencies, this study investigates the gender and socioeconomic differences in adolescents' digital skills in Japan. This study used data from the Programme for International Student Assessment (PISA), which was conducted in 2015 by the Organisation for Economic Co-operation and Development (OECD). The multiple regression analysis results demonstrated that gender and family socioeconomic status (SES) had statistically significant effects on adolescents' perceived ICT competencies. Specifically, the surveyed girls exhibited lower perceived ICT competence levels than boys, and family SES had a positive effect on adolescents' perceived ICT competencies. The results also indicated that ICT availability at home partially mediated the effect of family SES on adolescents' perceived ICT competence levels. In contrast, internet usage time suppressed the effect of SES on adolescents' perceived ICT competence levels. Moreover, the (positive) effects of ICT availability at home and internet usage time on adolescents' perceived ICT competencies were weaker for girls than for boys. It is presumed that girls are more likely to use ICTs for communicational purposes than boys, which may not improve their digital skills.