Researchers have examined a number of typologies of juvenile sex offenders, including victim age. Using data from psychological evaluations and the Multiphasic Sex Inventory‐II (MSI‐II; [Psychological assessment of sex offenders, 2010]), this study compared child offenders (i.e., victims were more than 4 years younger), peer offenders (i.e., victims were 4 years younger or less), and mixed offenders (i.e., both child and peer victims) on variables including victim, offender, and offense characteristics, and psychosexual development. Peer offenders had more severe sexual offenses, prior status/nonviolent charges, and issues with sexual functioning. Mixed offenders began offending at a younger age and were indiscriminate in gender and relationship of the victim. Mixed offenders were also more likely than child and peer offenders to have prior sex offender treatment, meaning they had previously failed treatment. As juvenile sex offenders are a heterogeneous group, these research findings suggest that child offenders, peer offenders, and mixed offenders’ treatment needs differ from each other.