The Multidimensional Subjective Financial Well-Being Scale (MSFWBS) has demonstrated strong validity in assessing subjective financial well-being among emerging adults in WEIRD (Western, Educated, Industrialized, Rich, and Democratic) contexts. However, evidence from developing countries remains limited and mixed. This study aimed to validate the Persian version of the MSFWBS among emerging adults in Iran. Adopting a contemporary view to validity, the scale was first translated and culturally adapted to ensure face and content validity. Subsequently, a series of Structural Equation Models were conducted to collect evidence of score structure, reliability, generalizability, and both convergent and criterion-related validity. Data were collected from 356 participants aged 18–29 in Sanandaj, Iran. Confirmatory factor analysis supported the original five-factor structure, with good fit indices and high internal consistency. Measurement invariance was confirmed across gender, age, living arrangement, and occupational status. Additionally, significant associations with personal income and life satisfaction provided further evidence for convergent and criterion-related validity, respectively. Overall, the findings suggest that the Persian version of the MSFWBS is a reliable and valid instrument for assessing subjective financial well-being among Iranian emerging adults. The study contributes to expanding research in non-WEIRD populations and supports the broader cross-cultural applicability of the MSFWBS in developing economies.