BACKGROUND: Most US adults are overweight or obese. Understanding differences in obesity prevalence across subpopulations could facilitate the development and dissemination of weight management services. OBJECTIVES: To inform Veterans Health Administration (VHA) weight management initiatives, we describe obesity prevalence among subpopulations of VHA patients. DESIGN: Cross-sectional descriptive analyses of fiscal year 2014 (FY2014) national VHA administrative and clinical data, stratified by gender. Differences ≥5% higher than the population mean were considered clinically significant. PARTICIPANTS: Veteran VHA primary care patients with a valid weight within ±365 days of their first FY2014 primary care visit, and a valid height (98% of primary care patients). MAIN MEASURES: We used VHA vital signs data to ascertain height and weight and calculate body mass index, and VHA outpatient, inpatient, and fee basis data to identify sociodemographic-and comorbidity-based subpopulations. KEY RESULTS: Among nearly five million primary care patients (347,112 women, 4,567,096 men), obesity prevalence was 41% (women 44%, men 41%), and overweight prevalence was 37% (women 31%, men 38%). Across the VHA's 140 facilities, obesity prevalence ranged from 28% to 49%. Among gender-stratified subpopulations, obesity prevalence was high among veterans under age 65 (age 18-44: women 40%, men 46%; age 45-64: women 49%, men 48%). Obesity prevalence varied across racial/ethnic and comorbidity subpopulations, with high obesity prevalence among black women (51%), women with schizophrenia (56%), and women and men with diabetes (68%, 56%). CONCLUSIONS: Overweight and obesity are common among veterans served by the VHA. VHA's weight management initiatives have the potential to avert long-term morbidity arising from obesity-related conditions. Highrisk groups-such as black women veterans, women veterans with schizophrenia, younger veterans, and Native Hawaiian/Other Pacific Islander and American Indian/ Alaska Native veterans-may require particular attention to ensure that systems improvement efforts at the population level do not inadvertently increase health disparities.