The goal of this study was to provide key prevalence rates for experiences with cyberbullying among tweens (children between the ages of 9 and 12 years old). We were also interested in the extent to which tweens engaged in helping behaviors when they observed cyberbullying. American tweens (n = 1034; mean age = 10.52, SD = 1.12) completed an online survey in which they reported on their experience with cyberbullying victimization, offending, and witnessing. Respondents were also asked how being cyberbullied made them feel, and to describe if they helped when they observed online mistreatment. Results revealed that about one in five tweens has been exposed to cyberbullying as a witness, a target, or an aggressor. This population has been historically understudied when it comes to their online experiences, and these findings highlight the need for deeper inquiry as well as additional guidance and support.