Despite strides toward gender equality in the workforce, women continue to face significant challenges, including the “glass ceiling” and the “leaky pipeline”, partially stemming from low occupational self-confidence. This study examined whether a climate of lookism leads to workplace mistreatment, undermining employees’ perceptions of job competence and career potential, with a focus on gender differences. Using a cross-sectional design, data from 699 Italian workers (42.8% male, 56.3% female) were analyzed through multi-group structural equation modeling. The model explored relationships between lookism climate, workplace incivility, imposter syndrome, and perceived employability. The results revealed a full serial mediation for women; lookism climate was positively related to workplace incivility, which in turn was related to imposter syndrome, negatively impacting perceived employability. For men, no serial mediation was found; lookism climate was directly related to both incivility and imposter syndrome, with no significant relationship between the two. Like women, men experienced a negative relationship between imposter syndrome and perceived employability, yet this relationship was stronger for men. This study highlights that identifying and addressing workplace climates that foster subtle mistreatment can prevent larger issues like the leaky pipeline, suggesting targeted organizational-level intervention and prevention strategies can enhance job competence perceptions and career potential for both genders.