To review the prevalence of depression among adolescents and young adults after moderate to severe TBI. A systematic literature search was conducted on literature published up to December 2018 in PubMed, EMBASE, Cochrane and PsychInfo. A systematic review of the identified literature was based on PRISMA guidelines. Risk of Bias was evaluated based on the aspects of Risk of Bias assessment described by the Agency of Health Research and Quality. Seven studies were deemed eligible and information on the prevalence of depression among adolescents and young adults (age 13–35) after moderate to severe TBI was extracted. Depression was assessed at 12 months (n = 2), >12 months (n = 2) or at varying times (n = 3) after TBI. The identified studies reported a prevalence proportion of depression from 1.6% to 60 The Risk of Bias assessment showed a range of study quality with the selection of subjects and analysis of attrition being problematic. Although literature is sparse and of varying quality, depression was found to be common among adolescents and young adults with moderate to severe TBI which implies a need to focus on depression in the rehabilitation process and calls for further research.