Purpose: Air pollution is a significant public health concern with well-documented effects on physical health, including asthma, cardiovascular disease, and respiratory illness. However, its impact on mental health, particularly among youth ages 10–24, remains less understood while mental health disorders among this population continue to rise. The purpose of this systematic review is to investigate the association between air pollution exposure and mental health disorders and to describe the most common disorders and symptoms. Methods: A systematic review, following PRISMA guidelines, was conducted for relevant articles published between 2023 and 2026. A total of 692 articles were identified, with 13 meeting inclusion criteria after screening. Observational studies were identified, screened, and qualitatively synthesized to examine associations between common air pollutants and mental health outcomes. Eligible studies assessed exposure to pollutants (i.e., particulate matter and gaseous pollutants) and measured outcomes using clinical diagnoses or validated symptom scales. Results: Across the reviewed literature, higher levels of air pollution exposure were associated with increased risk of anxiety, depression, and behavioral difficulties. While the strength of associations varied across studies, the findings suggest that air pollution may represent an underrecognized environmental contributor to youth mental health. This review clarifies current patterns in the literature and identifies key gaps in methodology and longitudinal evidence, providing direction for future research and informing public health discussions surrounding environmental risk factors.