PurposeThis study aims to examine the impact of managers’ inclusive leadership (IL) on knowledge-sharing (KS) behavior. Additionally, the authors consider the cross-level moderation effect of diversity in the biological sex of employees on the relationship between IL and employee KS behaviors.Design/methodology/approachA two-wave questionnaire survey was conducted in a large Japanese company. The sample included 827 employees (254 men and 573 women) in 129 groups. The authors, then, conducted a cross-level analysis using hierarchical linear modeling (HLM).FindingsIL promotes two types of KS among employees: knowledge donating (KD) and knowledge collecting (KC). Additionally, the moderating effects of employee biological-sex diversity on the relationship between IL and KS varied according to the KS type. IL had a positive effect on KD only in groups with higher biological-sex diversity, and did not affect groups with lower biological-sex diversity. Biological-sex diversity did not moderate the relationship between IL and KC.Practical implicationsThis study has practical implications, especially for personnel departments with high diversity in employees’ biological sex. Further, to improve employees’ KS behaviors, it may be important to develop managers’ IL skills.Originality/valueThis is the first study that explores the relationship between IL and KS and the first to provide evidence of the moderating effect of diversity of employee’s biological sex.