Background: The current study evaluated the associations between history of weight discrimination and race on pre-treatment depressive symptoms, treatment session attendance, and weight loss among Black and White adults enrolled in a 16-week obesity intervention. Methods: Participants (N = 271; mean BMI = 35.7 kg/m2; 59% Black; 92% women) reported prior experiences of weight discrimination and completed the Center for Epidemiological Studies Depression (CES-D) Scale at baseline. Weekly attendance at group sessions was recorded, and weight was measured at baseline and post-treatment. All models adjusted for baseline BMI, age, and sex. Results: Participants with a history of weight discrimination scored 2.4 points higher on the CES-D (B = 2.432, p =.012) and lost 2% less weight relative to those without weight discrimination (B = 0.023, p =.002). Race modified the association between weight discrimination and treatment session attendance, such that Black individuals attended fewer sessions if they had prior experience of weight discrimination, but prior weight discrimination was not significantly associated with treatment attendance among White individuals. Conclusion: Weight discrimination is associated with pre-treatment depressive symptoms and may hinder weight loss regardless of race. Black individuals may attend fewer weight loss treatment sessions if they have prior experience of weight discrimination.