The primary objective of this research was to assess age differences in the associations between cyberbullying victimization and bystanding and depression among 234 elementary school students (4th and 5th graders; 51% female), 363 middle school students (6th to 8th grades; 53% female), and 341 high school students (9th to 12th grades; 51% female) as well as the moderating effect of parental mediation in these relationships. Participants completed self-report questionnaires on their cyberbullying victimization and bystanding, as well as depressive symptoms. The findings revealed that high levels of instructive mediation buffered against depression associated with cyberbullying victimization and bystanding across all age groups, with the strongest effects found for middle school students. Lower levels of instructive mediation and higher levels of restrictive mediation increased the positive relationships between cyberbullying victimization and bystanding and depression. Co-viewing mediation did not moderate any of the associations. Parental mediation of technology use has the potential to alleviate the negative consequences associated with cyberbullying victimization and bystanding. The findings highlight the importance of tailoring prevention and intervention strategies to specific age groups and to parents.