Mobile games, those played on smartphones and tablets, are rapidly becoming a dominant form of entertainment for young people. Given most of these games provide opportunities for competitive and cooperative play, they have the potential to build and enhance existing social relationships and might also provide an avenue for negative social experiences such as bullying or trolling behaviors. Unfortunately, little is understood about the prevalence or effects of cyberbullying for young people in this new form of electronic play. The present research, conducted in March 2018, surveyed a large and representative cohort of British adolescents and their caregivers (n = 2,008) with the aim of building an empirical understanding of this phenomenon. Adolescents were asked about their play habits and experiences, and caregivers provided data on their children's socioeconomic and demographic background and psychosocial functioning. Of key interest was estimating how frequently adolescents encounter bullying in mobile games, the extent to which bullying impacts them, and the sources of support adolescents seek following these events. Results indicated that bullying in mobile games is relatively common (33.5%), although less than 1 in 10 experiences serious repeated bullying (9.3%). Analysis showed males, players from a minority ethnicity, and those whose caregivers identified as having conduct problems, were the most likely to report significant victimization. Furthermore, nearly 4 in 10 (39.4%) reported feeling fairly or very upset by the experience and parents (49.3%), not gaming platforms (4.2%), were most likely to be sought out for support after bullying was experienced. Results are discussed with respect to this soon-to-be expanding research area and recommendations for the use of open scientific methodologies are provided.