As Malaysia is moving rapidly toward an ageing nation, concern over issue on retirement preparedness has been intensified particularly among gig workers who operate outside formal employment systems. Characterised by income inconsistency and the absence of mandatory retirement contributions, gig workers face increased risks of financial insecurity during retirement. Although financial technology has become increasingly rooted in daily financial routines, research on its role in strengthening long-term retirement readiness among gig workers remains limited. This study investigates the relationship between fintech behavioural adoption and financial readiness for retirement among Malaysian gig workers, with perceived benefits and perceived risks as key predictors. Using a quantitative cross-sectional design, data were collected from 226 gig workers across major platform-based sectors. Partial least squares structural equation modelling (PLS-SEM) was used to assess both direct and indirect relationships of the model. The results uncover that perceived benefits and perceived risks exert a strong positive influence on fintech behavioural adoption, suggesting that risk-aware users remain actively engaged with fintech tools. Fintech behavioural adoption is found to have a significant positive impact on financial readiness for retirement, indicating that sustained use of digital financial tools supports better financial discipline, planning, and saving behaviour. Furthermore, fintech behavioural adoption mediates the relationships between both perceived benefits and perceived risks and retirement readiness. These findings highlight fintech adoption as a critical behavioural mechanism through which gig workers translate perceptions into long-term financial preparedness. The study concludes that strengthening fintech-based solutions, alongside targeted policy, and platform-level interventions, can play an important role in improving retirement readiness among gig workers and reducing future old-age vulnerability in Malaysia.