This research investigates the relationship between sustainable human resource management (SHRM) practices and employee happiness, with a focus on the mediating role of employee engagement. Using a sample of 473 women workers from one of India’s largest tea plantations, the study found a significant positive relationship between SHRM practices and employee happiness. Additionally, employee engagement was shown to mediate this relationship, indicating that SHRM practices enhance employee happiness primarily through increased engagement. The research aims to assess how sustainable human resource management affects workplace happiness among the women employees in the Indian tea plantation sector. The data was analyzed using IBM SPSS 25, and the research model was developed with WarpPLS 8.0. The study adopted Ehnert’s (2009) Sustainable Human Resource Management Practices, Singh & Aggarwal's (2017) Employee Happiness Scale (Happiness at Workplace), and Schaufeli et al.'s (2012) Employee Engagement Scale. The findings reveal a strong positive relationship between sustainable human resource management and employee happiness, with a correlation value of 0.943 at a significance level of 0.01. Moreover, there is a significant positive association between employee engagement and workplace happiness, with a correlation value of 0.947 and an R² of 0.99. These results confirm a robust positive relationship among sustainable human resource management, employee engagement, and employee happiness. This relationship emphasizes that fostering a positive work environment can significantly enhance employee engagement, leading to improved overall performance.