The mismatch between the study populations participating in oncology clinical trials and the composition of the targeted cancer population requires urgent amelioration. Regulatory requirements can mandate that trial sponsors enroll diverse study populations and ensure that regulatory revue prioritizes equity and inclusivity. A variety of projects directed at increasing accrual of underserved populations to oncology clinical trials emphasize best practices: broadened eligibility requirements for trials, simplification of trial procedures, community outreach through patient navigators, decentralization of clinical trial procedures and institution of telehealth, and funding to offset costs of travel and lodging. Substantial improvement will require major changes in culture in the educational and professional practice, research, and regulatory communities and will require major increases in public, corporate, and philanthropic funding.