The HIV epidemic has disproportionately affected young people, racial/ethnic minorities, and sexual and gender minorities. These inequities have significant implications for the health and wellbeing of young queer and transgender people of color. Pre-exposure prophylaxis (PrEP) is a safe and efficacious biomedical prevention modality that could dramatically reduce the number of new HIV infections. However, efforts to extend access to PrEP to those who stand to benefit the most, including young people, racial/ethnic minorities, and sexual/gender minorities, have fallen short. In this dissertation, I adopt an ecological model of HIV risk and prevention to contextualize health-related behaviors within the socio-structural environment that young people inhabit and identify factors relevant to engagement with PrEP. First, I used a systematic literature review to summarize and synthesize the existing body of literature on social networks as a factor in racial disparities in HIV among sexual minority men. In this review, I found that social network factors and structural factors are driving racial disparities in HIV and suggested that these same forces may underlie the inequities in PrEP uptake. To explore how network and structural factors are associated with progress along the PrEP continuum, I performed secondary analyses of two datasets related to social and sexual networks, economic vulnerability, HIV risk, and PrEP engagement among young sexual/gender minorities. I found that engagement with PrEP among young racial/ethnic minorities continues to lag behind engagement for adult White gay men. Additionally, I found that economic vulnerability was associated with lower PrEP engagement and that insurance status was a consistent correlate of engagement. Young people who perceived that their peers, both in social and sexual networks, were using PrEP showed significantly higher personal engagement with PrEP. The results of this dissertation suggest that an ecological understanding of HIV risk and prevention is needed if the full potential of PrEP as a tool for health equity is to be realized. Efforts to address inequities in HIV burden and PrEP uptake should aim to improve economic conditions for marginalized young people and bolster the capacity of social networks to promote PrEP engagement through community-engaged and peer-led interventions.