Objective: To examine the relationship between body mass index (BMI), and social cognitive measures of emotion in 8–19 year-olds. Method: Participants from the Philadelphia Neurodevelopmental cohort (N = 2, 869; ages 8–19) were categorized by age (grouped in two-year increments) and BMI (normal 5th to < 85th percentile; overweight 85th to < 95th percentile; and obese ≥95th percentile), in accordance with CDC criteria. Participants were medically and neurologically healthy; participants were not excluded based on psychiatric diagnoses. Participants completed the Penn Emotion Identification Test (EI) and the Penn Emotion Differentiation (ED) Test. Two 3x6 ANOVAs were used to examine BMI and age effects on EI and ED. Results: There was a main effect of BMI for ED, such that obese individuals were less accurate when compared to normal weight participants, but not overweight participants. Healthy weight participants were more accurate than both overweight and obese groups, F(2, 2833) = 9.53, p < .01, η2p = .01. There was no significant effect of BMI on EI. As expected, younger age groups (e.g., 8–9 year-olds) were less accurate compared to other age groups [EI F(5, 2851) = 47.48, p < .01, η2p = .08; ED F(5, 2833) = 111.20, p < .01, η2p = .16. No significant interactions emerged. Conclusion(s): BMI status appears related to emotional differentiation but not emotional identification in children and adolescents.