Transitional age youth experiencing homelessness (TAY-EH) represent an underserved and understudied population. While an increasing number of empirical interventions have sought to address the high burden of psychopathology in this population, findings remain mixed regarding intervention effectiveness. In this systematic review of behavioral health interventions for TAY-EH, we sought to examine the structural framework in which these interventions take place and how these structures include or exclude certain populations of youth. We also examined implementation practices to identify how interventions involving youth and community stakeholders effectively engage these populations. Based on PRISMA guidelines, searches of Medline, PsycInfo, Embase, Cochrane Central, Web of Science, and ClinicalTrials.gov databases were conducted, including English language literature published before October 2022. Eligible studies reported on interventions for adolescent or young adult populations ages 13-25years experiencing homelessness. The initial search yielded 3850 citations; 353 underwent full text review and 48 met inclusion criteria, of which there were 33 unique studies. Studies revealed a need for greater geographic distribution of empirically based interventions, as well as interventions targeting TAY-EH in rural settings. Studies varied greatly regarding their operationalizations of homelessness and their method of intervention implementation, but generally indicated a need for increased direct-street outreach in participant recruitment and improved incorporation of youth feedback into intervention design. To our knowledge, this is the first systematic review to examine the representation of various groups of TAY-EH in the literature on substance use and mental health interventions. Further intervention research engaging youth from various geographic locations and youth experiencing different forms of homelessness is needed to better address the behavioral health needs of a variety of TAY-EH.