ABSTRACTTHE FACTORS THAT INFLUENCE THE PHYSICAL ACTIVITY BEHAVIORS OF BLACK MEN Rashida Charles Lea Ann Matura Compared to men in other racial groups, Black men are among the least likely to engage in physical activity (PA). Their low PA engagement may contribute to why Black men have the lowest life expectancy in the United States and high rates of chronic conditions, including depression. This dissertation examines the complex relationships between PA behaviors, depression, the built environment, and social environment, with particular attention to discrimination as a key influencing factor. This dissertation includes an integrative review that synthesizes the current knowledge on the barriers and facilitators to PA engagement among Black men, followed by an explanatory sequential (QUANT → QUAL) mixed methods study with a photovoice component. The mixed methods study explored the PA behaviors, severity of depressive symptoms, and experiences with discrimination in 80 Black, millennial-aged men living in Philadelphia, Pennsylvania, at the time of data collection. A nested sample of 12 participants then completed a photovoice project exploring their barriers and facilitators to PA engagement. Results reveal that the social environment is the most significant determinant of PA engagement in Black men. The built environment was also frequently mentioned, but typically in social contexts. Community support, peer networks, and culturally inclusive spaces were identified as the strongest facilitators of PA engagement, while discrimination and gender role strain were the most significant barriers. These social factors not only shaped PA behaviors but also had profound implications for mental health outcomes. The findings highlight the critical importance of developing community-driven approaches and culturally tailored interventions to enhance PA participation and mental health outcomes in Black men. Through its exploration of unique barriers and facilitators to PA engagement, coupled with an examination of how social environments influence behavioral health, this study establishes a foundation for future research and interventions. This work advances our understanding of the complex interplay between PA engagement, depression, and discrimination, providing crucial insights for improving health outcomes among Black men.