The results show differences in the likelihood of unmet need for mental healthcare based on combinations of gender and mental health literacy level, with men having low mental health literacy being most at risk, and women with high mental health literacy being least at risk. This challenges generalisations of a gender difference in unmet need by showing heterogeneity among men and women based on mental health literacy. Men with low mental health literacy may be particularly in need of targeted interventions to reduce potential individual and societal consequences of their unmet need.