OBJECTIVE The internalization of weight bias is associated with clinically significant eating pathology among overweight adults. However, these relationships have not yet been assessed in lean individuals, who may perceive themselves to be overweight and subsequently internalize weight bias. The aim of the present study, therefore, was to determine whether lean individuals internalize weight bias and if the internalization of weight bias among lean respondents is associated with eating pathology. METHODS Participants were 197 lean (mean BMI: 22.28±1.89, range 15.80-24.98) adults who completed the Weight Bias Internalization Scale (WBIS) and measures of disordered eating behaviors and attitudes via an anonymous online survey. RESULTS Based on convergence of responses from the EDE-Q and QEWP-R, and using DSM-5 behavioral criteria, 10% and 15% of participants were classified into a binge eating and binge/purge group, respectively. WBIS scores were significantly higher among those with binge and/or purge behaviors compared to those without eating pathology. Bivariate correlations revealed positive associations between WBIS score and BMI, depression, and all EDE-Q subscales (restraint, eating concern, shape concern, weight concern). Logistic regressions indicated that internalized weight bias was significantly associated with binge/purge behaviors (OR=4.67, 95% CI: 2.38-9.17, p<.001) and binge eating (OR=2.29, 95% CI: 1.26-4.19, p<.01). CONCLUSIONS These novel findings suggest that lean individuals may internalize weight bias. Importantly, the internalization of weight bias among lean individuals is associated with clinically significant eating pathology.