While existing studies explore smartphone privacy setting risks for adolescents, they provide limited insight into the role of gender in these dynamics. This study aims to enhance adolescents’ awareness of the security risks associated with smartphone privacy leakage by focusing on how a cyber safety intervention lesson can affect knowledge of smartphone privacy settings, attitudes toward smartphone settings, and concerns about smartphone privacy. This study surveyed 376 high school students before and after a cyber safety lesson. Our study found that before the cyber safety intervention, females reported lower knowledge of smartphone settings than males. After the lesson, this gap narrowed, with both genders demonstrating more consistent understanding. Both genders showed lower attitudes towards smartphone privacy compared to knowledge, with males displaying the largest gap, reflecting the privacy paradox. Females expressed greater concern regarding location privacy, especially when tracked by unknown individuals, indicating that while both genders are aware of risks, females perceive them more acutely. The results suggest that targeted educational programs can effectively enhance adolescents’ knowledge, attitudes, and concerns about smartphone privacy, particularly in technical areas where gender gaps exist.