Having diverse participants in clinical trials ensures new drug products work well across different demographic groups, making health care safer and more effective for everyone. Information on the extent of Native Hawaiian and Pacific Islander participation in clinical trials is limited. To examine representation of Native Hawaiian and Pacific Islanders in clinical trials leading to the first US Food and Drug Administration (FDA) approvals for the 10 drug products with the top worldwide sales forecasts in 2024. Cross-sectional secondary analysis of existing data from clinical trials that took place from 2006 to 2021 in the US. All clinical trials that were included in the FDA first approval application for the 10 drug products were evaluated in this study. Data were analyzed from February to August 2024. Participation in a clinical drug trial. Comparison of the proportion of Native Hawaiian and Pacific Islander participation in clinical trials for the 10 drug products with top sales forecasts in 2024 to the Native Hawaiian and Pacific Islander population proportion. In this cross-sectional study of 139 062 individuals, Native Hawaiian and Pacific Islander participation in clinical trials for the 10 drug products with top sales forecasts was either unknown or low. For 6 of the 10 drug products (60%), the number of Native Hawaiian and Pacific Islander participants was not documented. All trials that reported Native Hawaiian and Pacific Islander participation had fewer Native Hawaiian and Pacific Islander participants than would be expected based on their US population proportion, with 2 of the differences being statistically significant. Of the trials that disaggregated Native Hawaiian and Pacific Islander participants from other racial groups, the number of Native Hawaiian and Pacific Islander participants was 8 for risankizumab-rzaa (0.38% of participants vs 0.49% of the population; percentage point difference, -0.11%; 95% CI, -0.37% to -0.15%), 7 for bictegravir/emtricitabine/tenofovir alafenamide (0.38% of participants vs 0.49% of the population; percentage point difference, -0.10%; 95% CI, -0.39% to 0.18%), 27 for 4vHPV/9vHPV (0.15% of participants vs 0.46% of the population; percentage point difference, -0.31%; 95% CI, -0.37% to -0.26%), and 90 for BNT162B2 COVID-19 vaccine (0.20% of participants vs 0.52% of the population; percentage point difference, -0.32; 95% CI, -0.36% to -0.27%). In this cross-sectional study, limited documentation and participation of Native Hawaiian and Pacific Islander individuals in clinical trials for drug products with top sales forecasts was found. This is especially concerning because Native Hawaiian and Pacific Islander individuals have a higher risk than other racial groups for type 2 diabetes, cancer, and several other conditions the products examined in this study treat. Given the importance of enrolling Native Hawaiian and Pacific Islander participants in clinical trials, sites should be established in key geographic regions, such as Hawai'i, and postmarket studies should be conducted within Native Hawaiian and Pacific Islander populations.