Background <p>Mental health is a critical aspect of overall well-being, encompassing not only the absence of mental disorders but also positive attributes such as stress management, and healthy relationships. Prior studies suggest that self-rated mental health varies across different cultures and sociodemographic characteristics. However, most studies on demographic variations in self-rated mental health have been conducted within specific countries or regions, leaving a gap in our understanding of how these factors influence mental health across different cultural contexts.</p> Methods <p>To address this gap, we leveraged a dataset of over 200,000 individuals from 22 countries to examine the distribution of self-rated mental health among key demographic variables such as age, gender, marital status, employment, education, and religious service attendance.</p> Results <p>Our findings reveal substantial country variations in self-rated mental health, measured as the mean score on a single-item Likert scale ranging from 0 (Poor) to 10 (Excellent). Participants in Tanzania, Kenya and Nigeria report the highest self-rated mental health scores, while those in Japan, Türkiye, and the United Kingdom report the lowest scores. Some demographic patterns – such as lower self-rated mental health among younger age groups and females, and higher self-rated mental health among those reporting regular religious service attendance – remain consistent across most countries. However, other patterns, such as the distribution of self-rated mental health by marital status, vary by country.</p> Conclusions <p>These descriptive findings highlight the need for context-specific mental health strategies and call for future research to identify social and structural factors of self-rated mental health.</p>