Background: We determined the race and ethnicity demographics and reporting trends of clinical trials leading to Food and Drug Administration (FDA) approvals for breast cancer., Methods: We collected enrollment and reporting data from clinical trials leading to FDA novel and new use approvals for breast cancer from 2010 to 2020 from Drugs@FDA, ClinicalTrials.gov, and associated journal manuscripts. Enrollment demographics were compared to the US cancer population estimates obtained using National Cancer Institute-Surveillance, Epidemiology, and End Results and 2010 US Census databases., Results: Seventeen drugs received approval based on 18 clinical trials with a total enrollment of 12,334. For approvals from 2010 to 2015 and from 2016 to 2020, there was no significant difference in race (80% vs. 91.6%, P = .34) or ethnicity reporting (20% vs. 33.3%, P = .5) on ClinicalTrials.Gov, manuscripts, and FDA labels. For trials that reported race and ethnicity, White, Asian, Black, and Hispanic patients represented 73.8%, 16.4%, 3.7%, and 10.4% of trial participants. Relative to their US cancer incidence, Black (31% of expected) patients were underrepresented compared with White (90% of expected), Hispanic (115%), and Asian (327% of expected) patients., Conclusion: We observed no significant difference in race and ethnicity reporting in pivotal clinical trials leading to FDA approval for breast cancer from 2010 to 2020. Black patients were underrepresented in these pivotal trials relative to White, Hispanic, and Asian patients. Ethnicity reporting remained low throughout the study period. Innovative approaches are needed to ensure equitable benefit of novel therapeutics., Competing Interests: Declaration of Competing Interest VKG declares: Genentech (speaking honorarium), Puma Biotechnology (scientific advisory; speaking honorarium); Seagen: (peaking honorarium), Hologic (speaking honorarium); Agendia (research funding to institution), Tizona Therapeutics (research funding to institution), SEngine Precision Medicine (equity), 3rdEyeBio (equity), Novilla Therapeutics (equity) AmunBio (equity), Phoenix Molecular Designs (scientific advisory board, equity), New Equilibrium Biosciences (scientific advisory board, equity)., (Copyright © 2023 Elsevier Inc. All rights reserved.)