Background Social media use has constituted to significant time spent online by adolescents globally, with its untoward effects increasingly being reported in many countries. Bullying through the use of such media has afflicted many adolescents to cause severe mental health concerns including self-harm and suicide.Aims The aims of this study are to examine the prevalence of cyberbullying in Singapore adolescents, its associations with psychosocial issues including self-harm and suicidal behaviors, and how adolescents seek help after being cybervictimised.Methods A representative sample of 3,319 school students aged between 12 and 17 years were recruited in this cross-sectional study and responded to a survey with scales measuring cyberbullying, psychosocial difficulties, self-harm, suicidal and help-seeking behaviors. The prevalence rate of cyberbullying was first explored using descriptive statistics, followed by Pearson chi-square tests for independence, one-way ANOVA tests and multinomial logistics regressions to examine its associations with various psychosocial issues.Results In the present study, 7.3% of adolescents reported being cybervictims only, 1.8% were cyberbullies only and 4.8% were cyberbully-victims. Compared to the non-involved group, all three cyberbullying-involved groups were associated with higher externalising problems [ F (3, 3290) = 62.06, p