Background: Despite the specific needs and challenges that kinship caregivers fostering adolescents face, they still receive less training, monitoring, and social support than non-kinship foster caregivers. Although the effectiveness of interventions and programmes targeting kinship care stakeholders has been previously assessed, a systematic review analysing the effectiveness of group interventions in kinship care outcomes for both kinship caregivers and adolescents in their care is still missing. Objectives: This systematic review aims to explore the impact of the group intervention format and to identify which components of this format positively impact kinship care placements that involve youth. Methods: We identified 13 studies through six databases. The extracted information was displayed through the following categories: location, target of intervention, research design, setting/format of intervention, group intervention description, sample, statistical tests and methods, outcomes, and key findings. Results: Results revealed that the assessed group interventions aimed to improve parenting skills and social support in kinship caregivers fostering youth. Improvements in both outcomes are likely common in group interventions focused on training parenting skills, with a group size of fewer than ten participants, approximately six to ten group sessions (90 min/session) conducted once a week and implemented interactive activities. Improvements in social support are more likely to be observed for interventions that combined group format and case management. Group intervention benefits relationships with peers, and permanency of the placement in kin youth. Discussion: Findings indicate that more evidence-based group interventions aimed at kinship caregivers fostering youth in kinship care should be designed and assessed to address their specific needs adequately. We have also discussed future research directions and their practicality.