This systematic review synthesizes research on existential crisis—the profound distress arising from questions about life’s meaning, death, freedom, and isolation—across diverse populations (youth, general, clinical) from 2000–2024. Following PRISMA guidelines, we identified peer-reviewed studies globally, summarizing their characteristics and findings. Results show that existential concerns are common in adolescence and emerging adulthood, and are closely linked with depression, anxiety, and identity issues. Major themes include struggles with meaninglessness, death anxiety, and social alienation; these often intensify under stress (e.g. COVID-19, economic instability) and may be buffered by coping strategies (e.g. spirituality, introspection). Indian studies are relatively sparse but indicate similar patterns of moderate existential anxiety among youth. We discuss implications for mental health interventions and note gaps for future research.