12136 Background: In the thick of the ongoing global crises of the COVID-19 pandemic, uprisings against anti-Black racism and police brutality, and anti-Asian racism and violence, Black, indigenous, and people of color (BIPOC) adolescent and young adult (AYA) cancer patients may be particularly vulnerable and exploited. Whilst embroiled in sociopolitical complexity, BIPOC AYAs are increasingly called upon to contribute as patient advocates in AYA oncology research and advocacy. Researchers, clinicians, and advocates in AYA oncology must dismantle long-standing racism and create meaningful structural change. The purpose of this study is to derive vital best practices for implementing antiracist patient engagement in AYA oncology research and advocacy that are co-developed by BIPOC AYA cancer patients and oncology professionals. Methods: We utilized a modified Delphi technique with a panel of BIPOC AYA cancer patients (n = 32) to build consensus opinions on professional recommendations from a prior study ( Cheung et al., 2021 ), and to generate antiracist best practices in patient engagement. The Delphi study was comprised of three consecutive and iterative survey rounds over the course of 8 months in 2021; participants were BIPOC AYAs diagnosed with cancer between ages 15-36 years. Results: Results detail best practices for the implementation of antiracist patient engagement across all research activities within the Patient-Centered Outcomes Research Institute’s (PCORI) Framework for Patient Engagement. For example, BIPOC AYAs agreed with oncology professionals’ high priority recommendation for including BIPOC AYAs at the highest levels of decision making in research topic selection. As such, a best practice is for researchers to ensure that such representatives not only hold BIPOC AYA identity, but also hold direct experience with the particular oncology diagnosis, issue, or other outcome of interest. Additionally, BIPOC AYAs concurred with oncology professionals’ high priority for “transparency, honesty, and trust” as a core principle for best practices in patient engagement. They further explained that trustworthy relationships are especially important when collaborating with teens and young adults, who are developmentally just coming into their own. When describing successful experiences of inclusion, participants ranked “build collaborative relationships with BIPOC AYA communities and listen to patients not usually heard” and “recruit a diverse range of BIPOC patients and let them give actual input into the study” as the highest priority best practices. Conclusions: Findings from this study are instructional for AYA oncology researchers, clinicians, and advocates to prevent harmful tokenism and implement genuine antiracist inclusion to advance health equity. Future research should investigate best practices within unique clinical settings.