This paper explores the relationship between globalisation and mental health by using the global dataset of high-, middle-, and low-income countries for the period 1970–2020. Although the consequences of globalisation on general health have been extensively studied, limited attention has been paid to investigating the implications on mental health. To show robustness, globalisation has been divided into three main dimensions such as economic globalisation, political globalisation, and social globalisation while, mental health has been classified through various indicators, i.e., mental disorder, anxiety disorder, and depressive disorder. The study used panel fixed effect techniques to demonstrate the quadratic effects of globalisation on mental health. A U-shaped curve relationship between globalisation (including economic, political, and political globalisation) and mental disorders, anxiety disorders, and depressive disorders was identified. However, findings also indicate an inverted U-shaped curve relationship between globalisation and mental health for high-income countries and a U-shaped curve relationship for middle- and low-income countries. Prioritizing mental health is crucial for overall well-being and productivity. Furthermore, a comprehensive policy implementation is strongly recommended to protect societies from mental distress when a country plans to expand globalisation worldwide.