Background <p> Existing socioeconomic status (SES) scales in India are limited by outdated income categories, urban-centric assumptions, and unidimensional frameworks that inadequately capture contemporary socioeconomic realities. This study aimed to develop and validate a theoretically grounded, multidimensional SES assessment tool suitable for Indian settings with potential relevance for South Asia.</p> Methods <p> A cross-sectional study was conducted to design and validate Solomon’s Socioeconomic Status Index (SESI). Scale development was informed by literature review, expert consultation, and focus group discussions. SESI comprises nine weighted dimensions: education (15%), occupation (15%), housing quality (20%), land ownership (10%), vehicle ownership (10%), business ownership (10%), durable assets (10%), locality type (5%), and digital access (5%). The tool was administered to 1,247 households across diverse geographic regions of India. Reliability was assessed using Cronbach’s alpha and split-half methods, while validity was evaluated using exploratory and confirmatory factor analyses and correlations with established SES scales.</p> Results <p> SESI demonstrated strong internal consistency (Cronbach’s α = 0.84) and high test–retest reliability (r = 0.89, p &lt; 0.001). Exploratory factor analysis identified a three-factor structure explaining 68.3% of variance, supported by confirmatory factor analysis (CFI = 0.94, RMSEA = 0.051). SESI showed significant correlations with the Modified Kuppuswamy Scale (r = 0.72) and BG Prasad Scale (r = 0.68), indicating good convergent validity.</p> Conclusion <p> SESI provides a reliable and theoretically informed multidimensional measure of socioeconomic status that captures both traditional and emerging determinants, including digital access. It offers improved precision for socioeconomic classification in health research and policy, with potential applicability to South Asian contexts subject to further validation.</p>