Background: Racial/ethnic minorities, elderly, and rural populations are underrepresented in clinical trials. Globally, gastrointestinal (GI) cancers represent more than a quarter of all cancers, and socioeconomic and lifestyle factors impact their incidence. Additionally, racial/ethnic disparities exist across GI tumor types, including early-onset colorectal cancer, and are associated with survival outcomes. Here we examine the proportion of women and minority participants with GI malignancies enrolled on SWOG Cancer Research Network therapeutic trials. Methods: We analyzed data on participants enrolled to SWOG phase I-III GI cancers treatment trials launched and completed between 2011-2021 according to sex, age (< 70 years vs ≥ 70 years), ethnicity (Hispanic vs not Hispanic), Race (Black vs Asian/Pacific Islander (PI) vs Native American vs White), insurance type (Medicaid or no insurance vs other), and residence types (classified as urban, large rural, small rural, and isolated small rural) using Rural-Urban Commuting Area (RUCA) codes based on zip codes. Participants reporting any category of Black, Asian/PI, Native American, or Hispanic were considered minority. Results: In total, n=1486 participants from 10 trials (S1005, S1115, S1201, S1310, S1313, S1406, S1505, S1513, S1613, S1815) conducted in 5 different GI cancers categories were enrolled, of whom 696 (46.8%) were women and 313 (21.1%) were minority. The five cancer types represented were biliary tract (34.0%), colorectal (10.8%), esophageal (4.8%), gastric/gastroesophageal junction (GEJ) (14.5%), and pancreatic (35.9%). Overall, 696 (46.8%) were female, 94 were Black (6.3%), 83 (5.6%) were Asian/PI, 5 (0.3%) were Native American, 132 were Hispanic (8.9%), 349 (23.5%) were ≥ 70 years, 1263 (85.0%) lived in an urban area, and 155 (10.4%) had Medicaid or no insurance. Minority participants were younger on average than non-minority participants (mean 58.7 vs 63.1, p<0.001), more likely to live in urban settings (92.7% vs. 82.9%, p<0.001) and have Medicaid or no insurance (26.5% vs. 6.1%, p<0.001). Over one-third (37.9%) of Hispanic, 22.3% of Black, and 13.3% Asian/PI participants vs 8.0% of White participants had Medicaid or no insurance. Women’s participation varied according to cancer type, ranging from 8.3% for esophageal to 56.2% for biliary tract, as did minority participation, ranging from 5.6% for esophageal to 36.6% for gastric/GEJ. Conclusions: Our findings suggest that racial/ethnic minorities, the elderly, and those residing in non-urban settings were less likely to enroll in SWOG GI cancers treatment trials than were whites, younger patients, and urban residents. Efforts are needed to enhance diverse enrollment, to break down barriers preventing minority participation, and to improve trial access to minimize disparities.