Psychological interventions such as behavioral activation (BA) that focus on overt behaviors rather than complex cognitive skills may be developmentally well-suited to address youth mental health problems. The current systematic review synthesized evidence on the characteristics, effectiveness and acceptability of behavioral activation (BA) to examine its role as a potential ‘active ingredient’ for alleviating depression and anxiety among young people aged 14 to 24 years. Methods: Evidence across the following sources were synthesized: (i) randomized control trials (RCT) evaluating interventions where BA has been used as a standalone intervention or as part of a multicomponent intervention, (ii) qualitative studies examining the acceptability of BA as an intervention or as a coping strategy among young people with lived experiences. Consultations with a youth advisory group (YAG) from India were used to draw inferences from existing evidence and identify future research priorities. Results: As part of the review, 23 RCTs were identified; three studies examined BA as a standalone intervention, and the remaining studies examined multicomponent intervention where BA was a constituent element. The intervention protocols varied in composition, with the number of intervention elements ranging between 5 to 18. There was promising but limited evidence in standalone interventions for thse effectiveness of BA for depression. The impact of BA in multicomponent interventions was difficult to evaluate in the absence of focal assessment of activation outcomes. Evidence from 37 additional qualitative studies of youth lived experience literature, corroborated by the YAG inputs, indicated that young people preferred using behavioral strategies similar to BA to cope with depression in their own life. Themes indicated that the activities that are important to an individual and their socio-contextual factors need to be considered in the planning and implementing BA intervention. Evidence for the use of BA in anxiety was limited across data sources. Conclusions: Overall, there was preliminary empirical evidence for the effectiveness and acceptability of BA for youth depression. Further research is needed to examine the components and mechanisms that contribute to its effectiveness as an active intervention ingredient for depression and anxiety.