ABSTRACT The University of Colorado Cancer Center (UCCC) catchment area is the State of Colorado (104,185 square miles and 5,842,076 people). In 2020, 27,290 Coloradans were diagnosed with cancer and over 8,000 died. UCCC analyzed data from the Colorado Central Cancer Registry and from local and national databases to characterize Colorado's cancer burden, risks, and disparities and to establish priorities. Priority areas include (a) burden from the top five incident and mortality cancers; (b) disparity populations (i.e., rural, Hispanic, poor); and (c) cancer risk factors (i.e., smoking, HPV infection, environmental exposures, low screening rates). The mission of the Office of Community Outreach and Engagement (COE) is to provide scientific direction and planning for UCCC efforts to conduct research and activities to address the priority areas and positively impact Coloradans. The COE also links UCCC state-of-the-art investigations with the needs and priorities of Colorado's communities. To address each priority area, COE has three overarching aims: (1) provide comprehensive up-to-date data, (2) facilitate and align basic, clinical, translational, and population health research with priorities, and (3) engage communities in science, education, dissemination/implementation, and advocacy. First, upon characterizing the catchment and setting priorities, COE led three community health assessments to gather baseline data to inform our work and further measure short and long-term progress on priorities. Second, COE built the infrastructure to align the UCCC programmatic research with the priorities and to link investigators with key community partners. Third, COE facilitates multiple service and research projects to educate and engage communities in cancer prevention, control, treatment, and survivorship efforts to reduce Colorado's cancer burden, risks, and disparities. These three aims are supported by five P30 supplements, as well as institutional funding for COE. To advance the work, COE facilitates research projects (e.g., R01), state-funded service projects, and pilot studies conducted by basic, clinical, translational, and population health investigators. COE conducts outreach and engagement activities to improve community participation in cancer research, education, and advocacy. UCCC has strong and well-established partnerships with stakeholders from government, employers, coalitions, advocacy and faith- based organizations, and state-wide healthcare systems. The 15 members of the Community Advisory Council (CAC) represent organizations that care for underserved populations in Colorado, as well as the Lieutenant Governor of Colorado – a multiple cancer survivor. To advance impact beyond Colorado, UCCC established the 4-Corners Collaborative with the NCI-designated cancer centers in Arizona, New Mexico, and Utah. The collaborative identifies and addresses priority cancers and disparity populations common to the 4-corn...